* [9front] merge3: a first draft
@ 2023-02-12 23:17 ori
2023-02-25 16:56 ` ori
0 siblings, 1 reply; 3+ messages in thread
From: ori @ 2023-02-12 23:17 UTC (permalink / raw)
To: 9front
I've been annoyed that we have to use ape/diff3 to merge
files for a while, so I finally sat down this weekend and
hacked 3-way merge capabilities into diff(1).
This is a rough draft, but here's the current approach.
3 way merging operates as follows:
With 3 files 'left', 'base', and 'right', we start by
producing the diff hunks against 'base' to 'left', and
'base' to 'right.
Then, for each hunk, pick the earlier diff hunk between
b/l and b/r, as you would with an array merge.
If the hunks overlap, adjust the sizes so that the common
section is the same size in both hunks, and emit a conflict
marker; otherwise, just emit that hunk, as well as the
unmodified text before it.
The bulk of this diff is refactoring diff(1) to allow two
diffs to be done at the same time, without overwriting each
other's globals.
diff 7f071685e9b7d9e32c1a9675f7fca0407d18e6e1 uncommitted
--- /dev/null
+++ b/sys/src/cmd/diff/diff.c
@@ -1,0 +1,84 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include "diff.h"
+
+void
+done(int status)
+{
+ switch(status)
+ {
+ case 0:
+ exits("");
+ case 1:
+ exits("some");
+ default:
+ exits("error");
+ }
+}
+
+void
+usage(void)
+{
+ fprint(2, "usage: %s [-abcefmnrw] file1 ... file2\n", argv0);
+ exits("usage");
+}
+
+void
+main(int argc, char *argv[])
+{
+ int i;
+ Dir *fsb, *tsb;
+
+ Binit(&stdout, 1, OWRITE);
+ ARGBEGIN{
+ case 'e':
+ case 'f':
+ case 'n':
+ case 'c':
+ case 'a':
+ case 'u':
+ mode = ARGC();
+ break;
+ case 'w':
+ bflag = 2;
+ break;
+
+ case 'b':
+ bflag = 1;
+ break;
+
+ case 'r':
+ rflag = 1;
+ break;
+
+ case 'm':
+ mflag = 1;
+ break;
+
+ case 'h':
+ default:
+ usage();
+ }ARGEND;
+ if (argc < 2)
+ usage();
+ if ((tsb = dirstat(argv[argc-1])) == nil)
+ sysfatal("can't stat %s", argv[argc-1]);
+ if (argc > 2) {
+ if (!DIRECTORY(tsb))
+ sysfatal("not directory: %s", argv[argc-1]);
+ mflag = 1;
+ } else {
+ if ((fsb = dirstat(argv[0])) == nil)
+ sysfatal("can't stat %s", argv[0]);
+ if (DIRECTORY(fsb) && DIRECTORY(tsb))
+ mflag = 1;
+ free(fsb);
+ }
+ free(tsb);
+ for (i = 0; i < argc-1; i++)
+ diff(argv[i], argv[argc-1], 0);
+
+ done(anychange);
+ /*NOTREACHED*/
+}
--- a/sys/src/cmd/diff/diff.h
+++ b/sys/src/cmd/diff/diff.h
@@ -1,13 +1,53 @@
-typedef struct Line Line;
+typedef struct Line Line;
+typedef struct Cand Cand;
+typedef struct Diff Diff;
+typedef struct Change Change;
struct Line {
int serial;
int value;
};
-extern Line *file[2];
-extern int len[2];
-extern long *ixold, *ixnew;
-extern int *J;
+
+struct Cand {
+ int x;
+ int y;
+ int pred;
+};
+
+struct Change
+{
+ int a;
+ int b;
+ int c;
+ int d;
+};
+
+struct Diff {
+ Cand cand;
+ Line *file[2], line;
+ int len[2];
+ int binary;
+ Line *sfile[2]; /*shortened by pruning common prefix and suffix*/
+ int slen[2];
+ int pref, suff; /*length of prefix and suffix*/
+ int *class; /*will be overlaid on file[0]*/
+ int *member; /*will be overlaid on file[1]*/
+ int *klist; /*will be overlaid on file[0] after class*/
+ Cand *clist; /* merely a free storage pot for candidates */
+ int clen;
+ int *J; /*will be overlaid on class*/
+ long *ixold; /*will be overlaid on klist*/
+ long *ixnew; /*will be overlaid on file[1]*/
+ char *file1;
+ char *file2;
+ Biobuf *input[2];
+ Biobuf *b0;
+ Biobuf *b1;
+ int firstchange;
+ Change *changes;
+ int nchanges;
+};
+
extern char mode;
extern char bflag;
extern char rflag;
@@ -14,19 +54,24 @@
extern char mflag;
extern int anychange;
extern Biobuf stdout;
-extern int binary;
#define MAXPATHLEN 1024
+#define DIRECTORY(s) ((s)->qid.type&QTDIR)
+#define REGULAR_FILE(s) ((s)->type == 'M' && !DIRECTORY(s))
+
int mkpathname(char *, char *, char *);
+char *mktmpfile(int, Dir **);
+char *statfile(char *, Dir **);
void *emalloc(unsigned);
void *erealloc(void *, unsigned);
void diff(char *, char *, int);
+void diffreg(char*, char*, char*, char*);
void diffdir(char *, char *, int);
-void diffreg(char *, char *, char *, char *);
-Biobuf *prepare(int, char *, char *);
-void panic(int, char *, ...);
-void check(Biobuf *, Biobuf *);
-void change(int, int, int, int);
-void flushchanges(void);
-
+void calcdiff(Diff *, char *, char *, char *, char *);
+Biobuf *prepare(Diff*, int, char *, char *);
+void check(Diff *, Biobuf *, Biobuf *);
+void change(Diff *, int, int, int, int);
+void freediff(Diff *);
+void flushchanges(Diff *);
+void fetch(Diff *d, long *f, int a, int b, Biobuf *bp, char *s);
--- a/sys/src/cmd/diff/diffdir.c
+++ b/sys/src/cmd/diff/diffdir.c
@@ -111,3 +111,45 @@
free(dirf);
free(dirt);
}
+
+void
+diff(char *f, char *t, int level)
+{
+ char *fp, *tp, *p, fb[MAXPATHLEN+1], tb[MAXPATHLEN+1];
+ Dir *fsb, *tsb;
+
+ fsb = nil;
+ tsb = nil;
+ if ((fp = statfile(f, &fsb)) == 0)
+ goto Return;
+ if ((tp = statfile(t, &tsb)) == 0)
+ goto Return;
+ if (DIRECTORY(fsb) && DIRECTORY(tsb)) {
+ if (rflag || level == 0)
+ diffdir(fp, tp, level);
+ else
+ Bprint(&stdout, "Common subdirectories: %s and %s\n", fp, tp);
+ }
+ else if (REGULAR_FILE(fsb) && REGULAR_FILE(tsb))
+ diffreg(fp, f, tp, t);
+ else {
+ if (REGULAR_FILE(fsb)) {
+ if ((p = utfrrune(f, '/')) == 0)
+ p = f;
+ else
+ p++;
+ if (mkpathname(tb, tp, p) == 0)
+ diffreg(fp, f, tb, t);
+ } else {
+ if ((p = utfrrune(t, '/')) == 0)
+ p = t;
+ else
+ p++;
+ if (mkpathname(fb, fp, p) == 0)
+ diffreg(fb, f, tp, t);
+ }
+ }
+Return:
+ free(fsb);
+ free(tsb);
+}
--- a/sys/src/cmd/diff/diffio.c
+++ b/sys/src/cmd/diff/diffio.c
@@ -4,10 +4,6 @@
#include <ctype.h>
#include "diff.h"
-static Biobuf *input[2];
-static char *file1, *file2;
-static int firstchange;
-
#define MAXLINELEN 4096
#define MIN(x, y) ((x) < (y) ? (x): (y))
@@ -104,7 +100,7 @@
}
Biobuf *
-prepare(int i, char *arg, char *orig)
+prepare(Diff *d, int i, char *arg, char *orig)
{
Line *p;
int j, h;
@@ -115,10 +111,10 @@
bp = Bopen(arg, OREAD);
if (!bp) {
- panic(mflag ? 0: 2, "cannot open %s: %r\n", arg);
+ sysfatal("cannot open %s: %r", arg);
return 0;
}
- if (binary)
+ if (d->binary)
return bp;
nbytes = Bread(bp, buf, MIN(1024, MAXLINELEN));
if (nbytes > 0) {
@@ -130,7 +126,7 @@
*/
cp += chartorune(&r, cp);
if (r == 0 || (r > 0x7f && r <= 0xa0)) {
- binary++;
+ d->binary++;
return bp;
}
}
@@ -139,14 +135,14 @@
p = emalloc(3*sizeof(Line));
for (j = 0; h = readhash(bp, buf); p[j].value = h)
p = erealloc(p, (++j+3)*sizeof(Line));
- len[i] = j;
- file[i] = p;
- input[i] = bp;
+ d->len[i] = j;
+ d->file[i] = p;
+ d->input[i] = bp;
if (i == 0) {
- file1 = orig;
- firstchange = 0;
+ d->file1 = orig;
+ d->firstchange = 0;
} else
- file2 = orig;
+ d->file2 = orig;
return bp;
}
@@ -175,31 +171,32 @@
* need to fix up for unexpected EOF's
*/
void
-check(Biobuf *bf, Biobuf *bt)
+check(Diff *d, Biobuf *bf, Biobuf *bt)
{
int f, t, flen, tlen;
char fbuf[MAXLINELEN], tbuf[MAXLINELEN];
- ixold[0] = ixnew[0] = 0;
- for (f = t = 1; f < len[0]; f++) {
+ d->ixold[0] = 0;
+ d->ixnew[0] = 0;
+ for (f = t = 1; f < d->len[0]; f++) {
flen = readline(bf, fbuf);
- ixold[f] = ixold[f-1] + flen + 1; /* ftell(bf) */
- if (J[f] == 0)
+ d->ixold[f] = d->ixold[f-1] + flen + 1; /* ftell(bf) */
+ if (d->J[f] == 0)
continue;
do {
tlen = readline(bt, tbuf);
- ixnew[t] = ixnew[t-1] + tlen + 1; /* ftell(bt) */
- } while (t++ < J[f]);
+ d->ixnew[t] = d->ixnew[t-1] + tlen + 1; /* ftell(bt) */
+ } while (t++ < d->J[f]);
if (bflag) {
flen = squishspace(fbuf);
tlen = squishspace(tbuf);
}
if (flen != tlen || strcmp(fbuf, tbuf))
- J[f] = 0;
+ d->J[f] = 0;
}
- while (t < len[1]) {
+ while (t < d->len[1]) {
tlen = readline(bt, tbuf);
- ixnew[t] = ixnew[t-1] + tlen + 1; /* fseek(bt) */
+ d->ixnew[t] = d->ixnew[t-1] + tlen + 1; /* fseek(bt) */
t++;
}
}
@@ -212,8 +209,8 @@
Bprint(&stdout, "%s%d", separator, b);
}
-static void
-fetch(long *f, int a, int b, Biobuf *bp, char *s)
+void
+fetch(Diff *d, long *f, int a, int b, Biobuf *bp, char *s)
{
char buf[MAXLINELEN];
int maxb;
@@ -220,10 +217,10 @@
if(a <= 1)
a = 1;
- if(bp == input[0])
- maxb = len[0];
+ if(bp == d->input[0])
+ maxb = d->len[0];
else
- maxb = len[1];
+ maxb = d->len[1];
if(b > maxb)
b = maxb;
if(a > maxb)
@@ -232,23 +229,12 @@
while (a++ <= b) {
readline(bp, buf);
Bprint(&stdout, "%s%s\n", s, buf);
+ Bflush(&stdout);
}
}
-typedef struct Change Change;
-struct Change
-{
- int a;
- int b;
- int c;
- int d;
-};
-
-Change *changes;
-int nchanges;
-
void
-change(int a, int b, int c, int d)
+change(Diff *df, int a, int b, int c, int d)
{
char verb;
char buf[4];
@@ -257,7 +243,7 @@
if (a > b && c > d)
return;
anychange = 1;
- if (mflag && firstchange == 0) {
+ if (mflag && df->firstchange == 0) {
if(mode) {
buf[0] = '-';
buf[1] = mode;
@@ -266,8 +252,8 @@
} else {
buf[0] = '\0';
}
- Bprint(&stdout, "diff %s%s %s\n", buf, file1, file2);
- firstchange = 1;
+ Bprint(&stdout, "diff %s%s %s\n", buf, df->file1, df->file2);
+ df->firstchange = 1;
}
verb = a > b ? 'a': c > d ? 'd': 'c';
switch(mode) {
@@ -281,10 +267,10 @@
range(c, d, ",");
break;
case 'n':
- Bprint(&stdout, "%s:", file1);
+ Bprint(&stdout, "%s:", df->file1);
range(a, b, ",");
Bprint(&stdout, " %c ", verb);
- Bprint(&stdout, "%s:", file2);
+ Bprint(&stdout, "%s:", df->file2);
range(c, d, ",");
break;
case 'f':
@@ -294,9 +280,9 @@
case 'c':
case 'a':
case 'u':
- if(nchanges%1024 == 0)
- changes = erealloc(changes, (nchanges+1024)*sizeof(changes[0]));
- ch = &changes[nchanges++];
+ if(df->nchanges%1024 == 0)
+ df->changes = erealloc(df->changes, (df->nchanges+1024)*sizeof(df->changes[0]));
+ ch = &df->changes[df->nchanges++];
ch->a = a;
ch->b = b;
ch->c = c;
@@ -305,11 +291,11 @@
}
Bputc(&stdout, '\n');
if (mode == 0 || mode == 'n') {
- fetch(ixold, a, b, input[0], "< ");
+ fetch(df, df->ixold, a, b, df->input[0], "< ");
if (a <= b && c <= d)
Bprint(&stdout, "---\n");
}
- fetch(ixnew, c, d, input[1], mode == 0 || mode == 'n' ? "> ": "");
+ fetch(df, df->ixnew, c, d, df->input[1], mode == 0 || mode == 'n' ? "> ": "");
if (mode != 0 && mode != 'n' && c <= d)
Bprint(&stdout, ".\n");
}
@@ -320,69 +306,69 @@
};
int
-changeset(int i)
+changeset(Diff *d, int i)
{
- while(i<nchanges && changes[i].b+1+2*Lines > changes[i+1].a)
+ while(i < d->nchanges && d->changes[i].b + 1 + 2*Lines > d->changes[i+1].a)
i++;
- if(i<nchanges)
+ if(i < d->nchanges)
return i+1;
- return nchanges;
+ return d->nchanges;
}
void
-flushchanges(void)
+flushchanges(Diff *df)
{
- int a, b, c, d, at, hdr;
- int i, j;
+ vlong a, b, c, d, at, hdr;
+ vlong i, j;
- if(nchanges == 0)
+ if(df->nchanges == 0)
return;
hdr = 0;
- for(i=0; i<nchanges; ){
- j = changeset(i);
- a = changes[i].a-Lines;
- b = changes[j-1].b+Lines;
- c = changes[i].c-Lines;
- d = changes[j-1].d+Lines;
+ for(i=0; i < df->nchanges; ){
+ j = changeset(df, i);
+ a = df->changes[i].a - Lines;
+ b = df->changes[j-1].b + Lines;
+ c = df->changes[i].c - Lines;
+ d = df->changes[j-1].d + Lines;
if(a < 1)
a = 1;
if(c < 1)
c = 1;
- if(b > len[0])
- b = len[0];
- if(d > len[1])
- d = len[1];
+ if(b > df->len[0])
+ b = df->len[0];
+ if(d > df->len[1])
+ d = df->len[1];
if(mode == 'a'){
a = 1;
- b = len[0];
+ b = df->len[0];
c = 1;
- d = len[1];
- j = nchanges;
+ d = df->len[1];
+ j = df->nchanges;
}
if(mode == 'u'){
if(!hdr){
- Bprint(&stdout, "--- %s\n", file1);
- Bprint(&stdout, "+++ %s\n", file2);
+ Bprint(&stdout, "--- %s\n", df->file1);
+ Bprint(&stdout, "+++ %s\n", df->file2);
hdr = 1;
}
- Bprint(&stdout, "@@ -%d,%d +%d,%d @@\n", a, b-a+1, c, d-c+1);
+ Bprint(&stdout, "@@ -%lld,%lld +%lld,%lld @@\n", a, b-a+1, c, d-c+1);
}else{
- Bprint(&stdout, "%s:", file1);
+ Bprint(&stdout, "%s:", df->file1);
range(a, b, ",");
Bprint(&stdout, " - ");
- Bprint(&stdout, "%s:", file2);
+ Bprint(&stdout, "%s:", df->file2);
range(c, d, ",");
Bputc(&stdout, '\n');
}
at = a;
for(; i<j; i++){
- fetch(ixold, at, changes[i].a-1, input[0], mode == 'u' ? " " : " ");
- fetch(ixold, changes[i].a, changes[i].b, input[0], mode == 'u' ? "-" : "- ");
- fetch(ixnew, changes[i].c, changes[i].d, input[1], mode == 'u' ? "+" : "+ ");
- at = changes[i].b+1;
+ fetch(df, df->ixold, at, df->changes[i].a-1, df->input[0], mode == 'u' ? " " : " ");
+ fetch(df, df->ixold, df->changes[i].a, df->changes[i].b, df->input[0], mode == 'u' ? "-" : "- ");
+ fetch(df, df->ixnew, df->changes[i].c, df->changes[i].d, df->input[1], mode == 'u' ? "+" : "+ ");
+ at = df->changes[i].b+1;
}
- fetch(ixold, at, b, input[0], mode == 'u' ? " " : " ");
+ fetch(df, df->ixold, at, b, df->input[0], mode == 'u' ? " " : " ");
}
- nchanges = 0;
+ df->nchanges = 0;
}
--- a/sys/src/cmd/diff/diffreg.c
+++ b/sys/src/cmd/diff/diffreg.c
@@ -66,30 +66,7 @@
* 3*(number of k-candidates installed), typically about
* 6n words for files of length n.
*/
-typedef struct Cand Cand;
-struct Cand {
- int x;
- int y;
- int pred;
-};
-
-Cand cand;
-Line *file[2], line;
-int len[2];
-int binary;
-Line *sfile[2]; /*shortened by pruning common prefix and suffix*/
-int slen[2];
-int pref, suff; /*length of prefix and suffix*/
-int *class; /*will be overlaid on file[0]*/
-int *member; /*will be overlaid on file[1]*/
-int *klist; /*will be overlaid on file[0] after class*/
-Cand *clist; /* merely a free storage pot for candidates */
-int clen;
-int *J; /*will be overlaid on class*/
-long *ixold; /*will be overlaid on klist*/
-long *ixnew; /*will be overlaid on file[1]*/
-
static void
sort(Line *a, int n) /*shellsort CACM #201*/
{
@@ -137,21 +114,21 @@
}
static void
-prune(void)
+prune(Diff *d)
{
int i,j;
- for(pref=0;pref<len[0]&&pref<len[1]&&
- file[0][pref+1].value==file[1][pref+1].value;
- pref++ ) ;
- for(suff=0;suff<len[0]-pref&&suff<len[1]-pref&&
- file[0][len[0]-suff].value==file[1][len[1]-suff].value;
- suff++) ;
+ for(d->pref = 0; d->pref < d->len[0] && d->pref < d->len[1] &&
+ d->file[0][d->pref+1].value == d->file[1][d->pref+1].value;
+ d->pref++) ;
+ for(d->suff=0; d->suff < d->len[0] - d->pref && d->suff < d->len[1] - d->pref &&
+ d->file[0][d->len[0] - d->suff].value == d->file[1][d->len[1] - d->suff].value;
+ d->suff++) ;
for(j=0;j<2;j++) {
- sfile[j] = file[j]+pref;
- slen[j] = len[j]-pref-suff;
- for(i=0;i<=slen[j];i++)
- sfile[j][i].serial = i;
+ d->sfile[j] = d->file[j]+d->pref;
+ d->slen[j] = d->len[j]-d->pref-d->suff;
+ for(i=0;i<=d->slen[j];i++)
+ d->sfile[j][i].serial = i;
}
}
@@ -184,30 +161,30 @@
}
static int
-newcand(int x, int y, int pred)
+newcand(Diff *d, int x, int y, int pred)
{
Cand *q;
- clist = erealloc(clist, (clen+1)*sizeof(Cand));
- q = clist + clen;
+ d->clist = erealloc(d->clist, (d->clen+1)*sizeof(Cand));
+ q = d->clist + d->clen;
q->x = x;
q->y = y;
q->pred = pred;
- return clen++;
+ return d->clen++;
}
static int
-search(int *c, int k, int y)
+search(Diff *d, int *c, int k, int y)
{
int i, j, l;
int t;
- if(clist[c[k]].y < y) /*quick look for typical case*/
+ if(d->clist[c[k]].y < y) /*quick look for typical case*/
return k+1;
i = 0;
j = k+1;
while((l=(i+j)/2) > i) {
- t = clist[c[l]].y;
+ t = d->clist[c[l]].y;
if(t > y)
j = l;
else if(t < y)
@@ -219,7 +196,7 @@
}
static int
-stone(int *a, int n, int *b, int *c)
+stone(Diff *d, int *a, int n, int *b, int *c)
{
int i, k,y;
int j, l;
@@ -227,7 +204,7 @@
int oldl;
k = 0;
- c[0] = newcand(0,0,0);
+ c[0] = newcand(d, 0, 0, 0);
for(i=1; i<=n; i++) {
j = a[i];
if(j==0)
@@ -236,20 +213,20 @@
oldl = 0;
oldc = c[0];
do {
- if(y <= clist[oldc].y)
+ if(y <= d->clist[oldc].y)
continue;
- l = search(c, k, y);
+ l = search(d, c, k, y);
if(l!=oldl+1)
oldc = c[l-1];
if(l<=k) {
- if(clist[c[l]].y <= y)
+ if(d->clist[c[l]].y <= y)
continue;
tc = c[l];
- c[l] = newcand(i,y,oldc);
+ c[l] = newcand(d, i, y, oldc);
oldc = tc;
oldl = l;
} else {
- c[l] = newcand(i,y,oldc);
+ c[l] = newcand(d, i,y,oldc);
k++;
break;
}
@@ -259,61 +236,23 @@
}
static void
-unravel(int p)
+unravel(Diff *d, int p)
{
int i;
Cand *q;
- for(i=0; i<=len[0]; i++) {
- if (i <= pref)
- J[i] = i;
- else if (i > len[0]-suff)
- J[i] = i+len[1]-len[0];
+ for(i=0; i<=d->len[0]; i++) {
+ if (i <= d->pref)
+ d->J[i] = i;
+ else if (i > d->len[0]-d->suff)
+ d->J[i] = i+d->len[1] - d->len[0];
else
- J[i] = 0;
+ d->J[i] = 0;
}
- for(q=clist+p;q->y!=0;q=clist+q->pred)
- J[q->x+pref] = q->y+pref;
+ for(q=d->clist+p; q->y != 0; q= d->clist + q->pred)
+ d->J[q->x+d->pref] = q->y+d->pref;
}
-static void
-output(void)
-{
- int m, i0, i1, j0, j1;
-
- m = len[0];
- J[0] = 0;
- J[m+1] = len[1]+1;
- if (mode != 'e') {
- for (i0 = 1; i0 <= m; i0 = i1+1) {
- while (i0 <= m && J[i0] == J[i0-1]+1)
- i0++;
- j0 = J[i0-1]+1;
- i1 = i0-1;
- while (i1 < m && J[i1+1] == 0)
- i1++;
- j1 = J[i1+1]-1;
- J[i1] = j1;
- change(i0, i1, j0, j1);
- }
- } else {
- for (i0 = m; i0 >= 1; i0 = i1-1) {
- while (i0 >= 1 && J[i0] == J[i0+1]-1 && J[i0])
- i0--;
- j0 = J[i0+1]-1;
- i1 = i0+1;
- while (i1 > 1 && J[i1-1] == 0)
- i1--;
- j1 = J[i1-1]+1;
- J[i1] = j1;
- change(i1 , i0, j1, j0);
- }
- }
- if (m == 0)
- change(1, 0, 1, len[1]);
- flushchanges();
-}
-
#define BUF 4096
static int
cmp(Biobuf* b1, Biobuf* b2)
@@ -361,21 +300,20 @@
}
void
-diffreg(char *f, char *fo, char *t, char *to)
+calcdiff(Diff *d, char *f, char *fo, char *t, char *to)
{
Biobuf *b0, *b1;
int k;
- binary = 0;
- b0 = prepare(0, f, fo);
+ b0 = prepare(d, 0, f, fo);
if (!b0)
return;
- b1 = prepare(1, t, to);
+ b1 = prepare(d, 1, t, to);
if (!b1) {
Bterm(b0);
return;
}
- if (binary){
+ if (d->binary){
// could use b0 and b1 but this is simpler.
if (cmp(b0, b1))
print("binary files %s %s differ\n", f, t);
@@ -383,38 +321,91 @@
Bterm(b1);
return;
}
- clen = 0;
- prune();
- sort(sfile[0], slen[0]);
- sort(sfile[1], slen[1]);
+ d->clen = 0;
+ prune(d);
+ sort(d->sfile[0], d->slen[0]);
+ sort(d->sfile[1], d->slen[1]);
- member = (int *)file[1];
- equiv(sfile[0], slen[0], sfile[1], slen[1], member);
- member = erealloc(member, (slen[1]+2)*sizeof(int));
+ d->member = (int *)d->file[1];
+ equiv(d->sfile[0], d->slen[0], d->sfile[1], d->slen[1], d->member);
+ d->member = erealloc(d->member, (d->slen[1]+2)*sizeof(int));
- class = (int *)file[0];
- unsort(sfile[0], slen[0], class);
- class = erealloc(class, (slen[0]+2)*sizeof(int));
+ d->class = (int *)d->file[0];
+ unsort(d->sfile[0], d->slen[0], d->class);
+ d->class = erealloc(d->class, (d->slen[0]+2)*sizeof(int));
- klist = emalloc((slen[0]+2)*sizeof(int));
- clist = emalloc(sizeof(Cand));
- k = stone(class, slen[0], member, klist);
- free(member);
- free(class);
+ d->klist = emalloc((d->slen[0]+2)*sizeof(int));
+ d->clist = emalloc(sizeof(Cand));
+ k = stone(d, d->class, d->slen[0], d->member, d->klist);
+ free(d->member);
+ free(d->class);
- J = emalloc((len[0]+2)*sizeof(int));
- unravel(klist[k]);
- free(clist);
- free(klist);
+ d->J = emalloc((d->len[0]+2)*sizeof(int));
+ unravel(d, d->klist[k]);
+ free(d->clist);
+ free(d->klist);
- ixold = emalloc((len[0]+2)*sizeof(long));
- ixnew = emalloc((len[1]+2)*sizeof(long));
+ d->ixold = emalloc((d->len[0]+2)*sizeof(long));
+ d->ixnew = emalloc((d->len[1]+2)*sizeof(long));
Bseek(b0, 0, 0); Bseek(b1, 0, 0);
- check(b0, b1);
- output();
- free(J);
- free(ixold);
- free(ixnew);
- Bterm(b0);
- Bterm(b1);
+ check(d, b0, b1);
+}
+
+static void
+output(Diff *d)
+{
+ int m, i0, i1, j0, j1;
+
+ m = d->len[0];
+ d->J[0] = 0;
+ d->J[m+1] = d->len[1]+1;
+ if (mode != 'e') {
+ for (i0 = 1; i0 <= m; i0 = i1+1) {
+ while (i0 <= m && d->J[i0] == d->J[i0-1]+1)
+ i0++;
+ j0 = d->J[i0-1]+1;
+ i1 = i0-1;
+ while (i1 < m && d->J[i1+1] == 0)
+ i1++;
+ j1 = d->J[i1+1]-1;
+ d->J[i1] = j1;
+ change(d, i0, i1, j0, j1);
+ }
+ } else {
+ for (i0 = m; i0 >= 1; i0 = i1-1) {
+ while (i0 >= 1 && d->J[i0] == d->J[i0+1]-1 && d->J[i0])
+ i0--;
+ j0 = d->J[i0+1]-1;
+ i1 = i0+1;
+ while (i1 > 1 && d->J[i1-1] == 0)
+ i1--;
+ j1 = d->J[i1-1]+1;
+ d->J[i1] = j1;
+ change(d, i1 , i0, j1, j0);
+ }
+ }
+ if (m == 0)
+ change(d, 1, 0, 1, d->len[1]);
+ flushchanges(d);
+}
+
+void
+diffreg(char *f, char *fo, char *t, char *to)
+{
+ Diff d;
+
+ memset(&d, 0, sizeof(d));
+ calcdiff(&d, f, fo, t, to);
+ output(&d);
+ freediff(&d);
+}
+
+void
+freediff(Diff *d)
+{
+ Bterm(d->input[0]);
+ Bterm(d->input[1]);
+ free(d->J);
+ free(d->ixold);
+ free(d->ixnew);
}
--- /dev/null
+++ b/sys/src/cmd/diff/merge3.c
@@ -1,0 +1,169 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include "diff.h"
+
+static int
+changecmp(void *a, void *b)
+{
+ return ((Change*)a)->a - ((Change*)b)->a;
+}
+
+static void
+addchange(Diff *df, int a, int b, int c, int d)
+{
+ Change *ch;
+
+ if (a > b && c > d)
+ return;
+ if(df->nchanges%1024 == 0)
+ df->changes = erealloc(df->changes, (df->nchanges+1024)*sizeof(df->changes[0]));
+ ch = &df->changes[df->nchanges++];
+ ch->a = a;
+ ch->b = b;
+ ch->c = c;
+ ch->d = d;
+}
+
+static void
+collect(Diff *d)
+{
+ int m, i0, i1, j0, j1;
+
+ m = d->len[0];
+ d->J[0] = 0;
+ d->J[m+1] = d->len[1]+1;
+ for (i0 = m; i0 >= 1; i0 = i1-1) {
+ while (i0 >= 1 && d->J[i0] == d->J[i0+1]-1 && d->J[i0])
+ i0--;
+ j0 = d->J[i0+1]-1;
+ i1 = i0+1;
+ while (i1 > 1 && d->J[i1-1] == 0)
+ i1--;
+ j1 = d->J[i1-1]+1;
+ d->J[i1] = j1;
+ addchange(d, i1 , i0, j1, j0);
+ }
+ if (m == 0)
+ change(d, 1, 0, 1, d->len[1]);
+ qsort(d->changes, d->nchanges, sizeof(Change), changecmp);
+}
+
+static int
+overlaps(Change *a, Change *b)
+{
+ if(a == nil || b == nil)
+ return 0;
+ if(a->a <= b->a)
+ return a->b >= b->a;
+ else
+ return b->b >= a->a;
+}
+
+char*
+merge(Diff *l, Diff *r)
+{
+ int il, ir, a, b, δ;
+ Change *lc, *rc;
+ char *status;
+ vlong ln;
+
+ il = 0;
+ ir = 0;
+ ln = 0;
+ status = nil;
+ collect(l);
+ collect(r);
+ while(il < l->nchanges || ir < r->nchanges){
+ lc = nil;
+ rc = nil;
+ if(il < l->nchanges)
+ lc = &l->changes[il];
+ if(ir < r->nchanges)
+ rc = &r->changes[ir];
+ if(overlaps(lc, rc)){
+ /*
+ * align the edges of the chunks
+ */
+ if(lc->a < rc->a){
+ a = lc->a;
+ δ = rc->a - lc->a;
+ rc->a -= δ;
+ rc->c -= δ;
+ }else{
+ a = rc->a;
+ δ = lc->a - rc->a;
+ lc->a -= δ;
+ lc->c -= δ;
+ }
+ if(lc->b > rc->b){
+ b = lc->b;
+ δ = lc->b - rc->b;
+ rc->b += δ;
+ rc->d += δ;
+ }else{
+ b = rc->b;
+ δ = rc->b - lc->b;
+ rc->b += δ;
+ rc->d += δ;
+ }
+ fetch(l, l->ixold, ln, a-1, l->input[0], "");
+ Bprint(&stdout, "<<<<<<<<<< %s\n", l->file2);
+ fetch(l, l->ixnew, lc->c, lc->d, l->input[1], "");
+ Bprint(&stdout, "========== common\n");
+ fetch(l, l->ixold, a, b, l->input[0], "");
+ Bprint(&stdout, "========== %s\n", r->file2);
+ fetch(r, r->ixnew, rc->c, rc->d, r->input[1], "");
+ Bprint(&stdout, ">>>>>>>>>>\n");
+ ln = b+1;
+ il++;
+ ir++;
+ status = "conflict";
+ }else if(rc == nil || lc->a < rc->a){
+ fetch(l, l->ixold, ln, lc->a-1, l->input[0], "");
+ fetch(l, l->ixnew, lc->c, lc->d, l->input[1], "");
+ ln = lc->b+1;
+ il++;
+ }else if(lc == nil || rc->a < lc->a){
+ fetch(l, l->ixold, ln, rc->a-1, l->input[0], "");
+ fetch(r, r->ixnew, rc->c, rc->d, r->input[1], "");
+ ln = lc->b+1;
+ ir++;
+ }else
+ abort();
+ }
+ if(ln < l->len[0])
+ fetch(l, l->ixold, ln, l->len[0], l->input[0], "");
+ return status;
+}
+
+void
+usage(void)
+{
+ fprint(2, "usage: %s theirs base ours\n", argv0);
+ exits("usage");
+}
+
+void
+main(int argc, char **argv)
+{
+ Diff l, r;
+ char *x;
+
+ ARGBEGIN{
+ default:
+ usage();
+ }ARGEND;
+
+ if(argc != 3)
+ usage();
+ Binit(&stdout, 1, OWRITE);
+ memset(&l, 0, sizeof(l));
+ memset(&r, 0, sizeof(r));
+ calcdiff(&l, argv[1], argv[1], argv[0], argv[0]);
+ calcdiff(&r, argv[1], argv[1], argv[2], argv[2]);
+ x = merge(&l, &r);
+ freediff(&l);
+ freediff(&r);
+ exits(x);
+}
--- a/sys/src/cmd/diff/mkfile
+++ b/sys/src/cmd/diff/mkfile
@@ -1,13 +1,13 @@
< /$objtype/mkfile
-TARG=diff
+TARG=diff merge3
OFILES=\
diffdir.$O\
diffio.$O\
diffreg.$O\
- main.$O\
+ util.$O
HFILES=diff.h
BIN=/$objtype/bin
-</sys/src/cmd/mkone
+</sys/src/cmd/mkmany
--- /dev/null
+++ b/sys/src/cmd/diff/util.c
@@ -1,0 +1,107 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include "diff.h"
+
+Biobuf stdout;
+char mode; /* '\0', 'e', 'f', 'h' */
+char bflag; /* ignore multiple and trailing blanks */
+char rflag; /* recurse down directory trees */
+char mflag; /* pseudo flag: doing multiple files, one dir */
+int anychange;
+
+static char *tmp[] = {"/tmp/diff1XXXXXXXXXXX", "/tmp/diff2XXXXXXXXXXX"};
+static int whichtmp;
+
+void *
+emalloc(unsigned n)
+{
+ register void *p;
+
+ if ((p = malloc(n)) == 0)
+ sysfatal("malloc: %r");
+ return p;
+}
+
+void *
+erealloc(void *p, unsigned n)
+{
+ void *rp;
+
+ if ((rp = realloc(p, n)) == 0)
+ sysfatal("realloc: %r");
+ return rp;
+}
+
+int
+mkpathname(char *pathname, char *path, char *name)
+{
+ if (strlen(path) + strlen(name) > MAXPATHLEN) {
+ sysfatal("pathname %s/%s too long", path, name);
+ return 1;
+ }
+ sprint(pathname, "%s/%s", path, name);
+ return 0;
+}
+
+char *
+mktmpfile(int input, Dir **sb)
+{
+ int fd, i;
+ char *p;
+ char buf[8192];
+
+ p = mktemp(tmp[whichtmp++]);
+ fd = create(p, OWRITE|ORCLOSE, 0600);
+ if (fd < 0) {
+ sysfatal("cannot create %s: %r", p);
+ return 0;
+ }
+ while ((i = read(input, buf, sizeof(buf))) > 0) {
+ if ((i = write(fd, buf, i)) < 0)
+ break;
+ }
+ *sb = dirfstat(fd);
+ close(fd);
+ if (i < 0) {
+ sysfatal("cannot read/write %s: %r", p);
+ return 0;
+ }
+ return p;
+}
+
+void
+rmtmpfiles(void)
+{
+ while (whichtmp > 0) {
+ whichtmp--;
+ remove(tmp[whichtmp]);
+ }
+}
+
+char *
+statfile(char *file, Dir **sb)
+{
+ Dir *dir;
+ int input;
+
+ dir = dirstat(file);
+ if(dir == nil) {
+ if (strcmp(file, "-") || (dir = dirfstat(0)) == nil) {
+ sysfatal("cannot stat %s: %r", file);
+ return 0;
+ }
+ free(dir);
+ return mktmpfile(0, sb);
+ } else if (!REGULAR_FILE(dir) && !DIRECTORY(dir)) {
+ free(dir);
+ if ((input = open(file, OREAD)) == -1) {
+ sysfatal("cannot open %s: %r", file);
+ return 0;
+ }
+ file = mktmpfile(input, sb);
+ close(input);
+ } else
+ *sb = dir;
+ return file;
+}
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [9front] merge3: a first draft
2023-02-12 23:17 [9front] merge3: a first draft ori
@ 2023-02-25 16:56 ` ori
2023-03-04 20:06 ` ori
0 siblings, 1 reply; 3+ messages in thread
From: ori @ 2023-02-25 16:56 UTC (permalink / raw)
To: 9front
Quoth ori@eigenstate.org:
> I've been annoyed that we have to use ape/diff3 to merge
> files for a while, so I finally sat down this weekend and
> hacked 3-way merge capabilities into diff(1).
>
> This is a rough draft, but here's the current approach.
>
> 3 way merging operates as follows:
>
Now bugfixed, and with tests.
diff e6c6217b35c319127f0200fdb28ec86e1b774a4f uncommitted
--- /dev/null
+++ b/sys/src/cmd/diff/diff.c
@@ -1,0 +1,84 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include "diff.h"
+
+void
+done(int status)
+{
+ switch(status)
+ {
+ case 0:
+ exits("");
+ case 1:
+ exits("some");
+ default:
+ exits("error");
+ }
+}
+
+void
+usage(void)
+{
+ fprint(2, "usage: %s [-abcefmnrw] file1 ... file2\n", argv0);
+ exits("usage");
+}
+
+void
+main(int argc, char *argv[])
+{
+ int i;
+ Dir *fsb, *tsb;
+
+ Binit(&stdout, 1, OWRITE);
+ ARGBEGIN{
+ case 'e':
+ case 'f':
+ case 'n':
+ case 'c':
+ case 'a':
+ case 'u':
+ mode = ARGC();
+ break;
+ case 'w':
+ bflag = 2;
+ break;
+
+ case 'b':
+ bflag = 1;
+ break;
+
+ case 'r':
+ rflag = 1;
+ break;
+
+ case 'm':
+ mflag = 1;
+ break;
+
+ case 'h':
+ default:
+ usage();
+ }ARGEND;
+ if (argc < 2)
+ usage();
+ if ((tsb = dirstat(argv[argc-1])) == nil)
+ sysfatal("can't stat %s", argv[argc-1]);
+ if (argc > 2) {
+ if (!DIRECTORY(tsb))
+ sysfatal("not directory: %s", argv[argc-1]);
+ mflag = 1;
+ } else {
+ if ((fsb = dirstat(argv[0])) == nil)
+ sysfatal("can't stat %s", argv[0]);
+ if (DIRECTORY(fsb) && DIRECTORY(tsb))
+ mflag = 1;
+ free(fsb);
+ }
+ free(tsb);
+ for (i = 0; i < argc-1; i++)
+ diff(argv[i], argv[argc-1], 0);
+
+ done(anychange);
+ /*NOTREACHED*/
+}
--- a/sys/src/cmd/diff/diff.h
+++ b/sys/src/cmd/diff/diff.h
@@ -1,13 +1,53 @@
-typedef struct Line Line;
+typedef struct Line Line;
+typedef struct Cand Cand;
+typedef struct Diff Diff;
+typedef struct Change Change;
struct Line {
int serial;
int value;
};
-extern Line *file[2];
-extern int len[2];
-extern long *ixold, *ixnew;
-extern int *J;
+
+struct Cand {
+ int x;
+ int y;
+ int pred;
+};
+
+struct Change
+{
+ int a;
+ int b;
+ int c;
+ int d;
+};
+
+struct Diff {
+ Cand cand;
+ Line *file[2], line;
+ int len[2];
+ int binary;
+ Line *sfile[2]; /*shortened by pruning common prefix and suffix*/
+ int slen[2];
+ int pref, suff; /*length of prefix and suffix*/
+ int *class; /*will be overlaid on file[0]*/
+ int *member; /*will be overlaid on file[1]*/
+ int *klist; /*will be overlaid on file[0] after class*/
+ Cand *clist; /* merely a free storage pot for candidates */
+ int clen;
+ int *J; /*will be overlaid on class*/
+ long *ixold; /*will be overlaid on klist*/
+ long *ixnew; /*will be overlaid on file[1]*/
+ char *file1;
+ char *file2;
+ Biobuf *input[2];
+ Biobuf *b0;
+ Biobuf *b1;
+ int firstchange;
+ Change *changes;
+ int nchanges;
+};
+
extern char mode;
extern char bflag;
extern char rflag;
@@ -14,19 +54,24 @@
extern char mflag;
extern int anychange;
extern Biobuf stdout;
-extern int binary;
#define MAXPATHLEN 1024
+#define DIRECTORY(s) ((s)->qid.type&QTDIR)
+#define REGULAR_FILE(s) ((s)->type == 'M' && !DIRECTORY(s))
+
int mkpathname(char *, char *, char *);
+char *mktmpfile(int, Dir **);
+char *statfile(char *, Dir **);
void *emalloc(unsigned);
void *erealloc(void *, unsigned);
void diff(char *, char *, int);
+void diffreg(char*, char*, char*, char*);
void diffdir(char *, char *, int);
-void diffreg(char *, char *, char *, char *);
-Biobuf *prepare(int, char *, char *);
-void panic(int, char *, ...);
-void check(Biobuf *, Biobuf *);
-void change(int, int, int, int);
-void flushchanges(void);
-
+void calcdiff(Diff *, char *, char *, char *, char *);
+Biobuf *prepare(Diff*, int, char *, char *);
+void check(Diff *, Biobuf *, Biobuf *);
+void change(Diff *, int, int, int, int);
+void freediff(Diff *);
+void flushchanges(Diff *);
+void fetch(Diff *d, long *f, int a, int b, Biobuf *bp, char *s);
--- a/sys/src/cmd/diff/diffdir.c
+++ b/sys/src/cmd/diff/diffdir.c
@@ -111,3 +111,45 @@
free(dirf);
free(dirt);
}
+
+void
+diff(char *f, char *t, int level)
+{
+ char *fp, *tp, *p, fb[MAXPATHLEN+1], tb[MAXPATHLEN+1];
+ Dir *fsb, *tsb;
+
+ fsb = nil;
+ tsb = nil;
+ if ((fp = statfile(f, &fsb)) == 0)
+ goto Return;
+ if ((tp = statfile(t, &tsb)) == 0)
+ goto Return;
+ if (DIRECTORY(fsb) && DIRECTORY(tsb)) {
+ if (rflag || level == 0)
+ diffdir(fp, tp, level);
+ else
+ Bprint(&stdout, "Common subdirectories: %s and %s\n", fp, tp);
+ }
+ else if (REGULAR_FILE(fsb) && REGULAR_FILE(tsb))
+ diffreg(fp, f, tp, t);
+ else {
+ if (REGULAR_FILE(fsb)) {
+ if ((p = utfrrune(f, '/')) == 0)
+ p = f;
+ else
+ p++;
+ if (mkpathname(tb, tp, p) == 0)
+ diffreg(fp, f, tb, t);
+ } else {
+ if ((p = utfrrune(t, '/')) == 0)
+ p = t;
+ else
+ p++;
+ if (mkpathname(fb, fp, p) == 0)
+ diffreg(fb, f, tp, t);
+ }
+ }
+Return:
+ free(fsb);
+ free(tsb);
+}
--- a/sys/src/cmd/diff/diffio.c
+++ b/sys/src/cmd/diff/diffio.c
@@ -4,10 +4,6 @@
#include <ctype.h>
#include "diff.h"
-static Biobuf *input[2];
-static char *file1, *file2;
-static int firstchange;
-
#define MAXLINELEN 4096
#define MIN(x, y) ((x) < (y) ? (x): (y))
@@ -104,7 +100,7 @@
}
Biobuf *
-prepare(int i, char *arg, char *orig)
+prepare(Diff *d, int i, char *arg, char *orig)
{
Line *p;
int j, h;
@@ -115,10 +111,10 @@
bp = Bopen(arg, OREAD);
if (!bp) {
- panic(mflag ? 0: 2, "cannot open %s: %r\n", arg);
+ sysfatal("cannot open %s: %r", arg);
return 0;
}
- if (binary)
+ if (d->binary)
return bp;
nbytes = Bread(bp, buf, MIN(1024, MAXLINELEN));
if (nbytes > 0) {
@@ -130,7 +126,7 @@
*/
cp += chartorune(&r, cp);
if (r == 0 || (r > 0x7f && r <= 0xa0)) {
- binary++;
+ d->binary++;
return bp;
}
}
@@ -139,14 +135,14 @@
p = emalloc(3*sizeof(Line));
for (j = 0; h = readhash(bp, buf); p[j].value = h)
p = erealloc(p, (++j+3)*sizeof(Line));
- len[i] = j;
- file[i] = p;
- input[i] = bp;
+ d->len[i] = j;
+ d->file[i] = p;
+ d->input[i] = bp;
if (i == 0) {
- file1 = orig;
- firstchange = 0;
+ d->file1 = orig;
+ d->firstchange = 0;
} else
- file2 = orig;
+ d->file2 = orig;
return bp;
}
@@ -175,31 +171,32 @@
* need to fix up for unexpected EOF's
*/
void
-check(Biobuf *bf, Biobuf *bt)
+check(Diff *d, Biobuf *bf, Biobuf *bt)
{
int f, t, flen, tlen;
char fbuf[MAXLINELEN], tbuf[MAXLINELEN];
- ixold[0] = ixnew[0] = 0;
- for (f = t = 1; f < len[0]; f++) {
+ d->ixold[0] = 0;
+ d->ixnew[0] = 0;
+ for (f = t = 1; f < d->len[0]; f++) {
flen = readline(bf, fbuf);
- ixold[f] = ixold[f-1] + flen + 1; /* ftell(bf) */
- if (J[f] == 0)
+ d->ixold[f] = d->ixold[f-1] + flen + 1; /* ftell(bf) */
+ if (d->J[f] == 0)
continue;
do {
tlen = readline(bt, tbuf);
- ixnew[t] = ixnew[t-1] + tlen + 1; /* ftell(bt) */
- } while (t++ < J[f]);
+ d->ixnew[t] = d->ixnew[t-1] + tlen + 1; /* ftell(bt) */
+ } while (t++ < d->J[f]);
if (bflag) {
flen = squishspace(fbuf);
tlen = squishspace(tbuf);
}
if (flen != tlen || strcmp(fbuf, tbuf))
- J[f] = 0;
+ d->J[f] = 0;
}
- while (t < len[1]) {
+ while (t < d->len[1]) {
tlen = readline(bt, tbuf);
- ixnew[t] = ixnew[t-1] + tlen + 1; /* fseek(bt) */
+ d->ixnew[t] = d->ixnew[t-1] + tlen + 1; /* fseek(bt) */
t++;
}
}
@@ -212,8 +209,8 @@
Bprint(&stdout, "%s%d", separator, b);
}
-static void
-fetch(long *f, int a, int b, Biobuf *bp, char *s)
+void
+fetch(Diff *d, long *f, int a, int b, Biobuf *bp, char *s)
{
char buf[MAXLINELEN];
int maxb;
@@ -220,10 +217,10 @@
if(a <= 1)
a = 1;
- if(bp == input[0])
- maxb = len[0];
+ if(bp == d->input[0])
+ maxb = d->len[0];
else
- maxb = len[1];
+ maxb = d->len[1];
if(b > maxb)
b = maxb;
if(a > maxb)
@@ -232,23 +229,12 @@
while (a++ <= b) {
readline(bp, buf);
Bprint(&stdout, "%s%s\n", s, buf);
+ Bflush(&stdout);
}
}
-typedef struct Change Change;
-struct Change
-{
- int a;
- int b;
- int c;
- int d;
-};
-
-Change *changes;
-int nchanges;
-
void
-change(int a, int b, int c, int d)
+change(Diff *df, int a, int b, int c, int d)
{
char verb;
char buf[4];
@@ -257,7 +243,7 @@
if (a > b && c > d)
return;
anychange = 1;
- if (mflag && firstchange == 0) {
+ if (mflag && df->firstchange == 0) {
if(mode) {
buf[0] = '-';
buf[1] = mode;
@@ -266,8 +252,8 @@
} else {
buf[0] = '\0';
}
- Bprint(&stdout, "diff %s%s %s\n", buf, file1, file2);
- firstchange = 1;
+ Bprint(&stdout, "diff %s%s %s\n", buf, df->file1, df->file2);
+ df->firstchange = 1;
}
verb = a > b ? 'a': c > d ? 'd': 'c';
switch(mode) {
@@ -281,10 +267,10 @@
range(c, d, ",");
break;
case 'n':
- Bprint(&stdout, "%s:", file1);
+ Bprint(&stdout, "%s:", df->file1);
range(a, b, ",");
Bprint(&stdout, " %c ", verb);
- Bprint(&stdout, "%s:", file2);
+ Bprint(&stdout, "%s:", df->file2);
range(c, d, ",");
break;
case 'f':
@@ -294,9 +280,9 @@
case 'c':
case 'a':
case 'u':
- if(nchanges%1024 == 0)
- changes = erealloc(changes, (nchanges+1024)*sizeof(changes[0]));
- ch = &changes[nchanges++];
+ if(df->nchanges%1024 == 0)
+ df->changes = erealloc(df->changes, (df->nchanges+1024)*sizeof(df->changes[0]));
+ ch = &df->changes[df->nchanges++];
ch->a = a;
ch->b = b;
ch->c = c;
@@ -305,11 +291,11 @@
}
Bputc(&stdout, '\n');
if (mode == 0 || mode == 'n') {
- fetch(ixold, a, b, input[0], "< ");
+ fetch(df, df->ixold, a, b, df->input[0], "< ");
if (a <= b && c <= d)
Bprint(&stdout, "---\n");
}
- fetch(ixnew, c, d, input[1], mode == 0 || mode == 'n' ? "> ": "");
+ fetch(df, df->ixnew, c, d, df->input[1], mode == 0 || mode == 'n' ? "> ": "");
if (mode != 0 && mode != 'n' && c <= d)
Bprint(&stdout, ".\n");
}
@@ -320,69 +306,69 @@
};
int
-changeset(int i)
+changeset(Diff *d, int i)
{
- while(i<nchanges && changes[i].b+1+2*Lines > changes[i+1].a)
+ while(i < d->nchanges && d->changes[i].b + 1 + 2*Lines > d->changes[i+1].a)
i++;
- if(i<nchanges)
+ if(i < d->nchanges)
return i+1;
- return nchanges;
+ return d->nchanges;
}
void
-flushchanges(void)
+flushchanges(Diff *df)
{
- int a, b, c, d, at, hdr;
- int i, j;
+ vlong a, b, c, d, at, hdr;
+ vlong i, j;
- if(nchanges == 0)
+ if(df->nchanges == 0)
return;
hdr = 0;
- for(i=0; i<nchanges; ){
- j = changeset(i);
- a = changes[i].a-Lines;
- b = changes[j-1].b+Lines;
- c = changes[i].c-Lines;
- d = changes[j-1].d+Lines;
+ for(i=0; i < df->nchanges; ){
+ j = changeset(df, i);
+ a = df->changes[i].a - Lines;
+ b = df->changes[j-1].b + Lines;
+ c = df->changes[i].c - Lines;
+ d = df->changes[j-1].d + Lines;
if(a < 1)
a = 1;
if(c < 1)
c = 1;
- if(b > len[0])
- b = len[0];
- if(d > len[1])
- d = len[1];
+ if(b > df->len[0])
+ b = df->len[0];
+ if(d > df->len[1])
+ d = df->len[1];
if(mode == 'a'){
a = 1;
- b = len[0];
+ b = df->len[0];
c = 1;
- d = len[1];
- j = nchanges;
+ d = df->len[1];
+ j = df->nchanges;
}
if(mode == 'u'){
if(!hdr){
- Bprint(&stdout, "--- %s\n", file1);
- Bprint(&stdout, "+++ %s\n", file2);
+ Bprint(&stdout, "--- %s\n", df->file1);
+ Bprint(&stdout, "+++ %s\n", df->file2);
hdr = 1;
}
- Bprint(&stdout, "@@ -%d,%d +%d,%d @@\n", a, b-a+1, c, d-c+1);
+ Bprint(&stdout, "@@ -%lld,%lld +%lld,%lld @@\n", a, b-a+1, c, d-c+1);
}else{
- Bprint(&stdout, "%s:", file1);
+ Bprint(&stdout, "%s:", df->file1);
range(a, b, ",");
Bprint(&stdout, " - ");
- Bprint(&stdout, "%s:", file2);
+ Bprint(&stdout, "%s:", df->file2);
range(c, d, ",");
Bputc(&stdout, '\n');
}
at = a;
for(; i<j; i++){
- fetch(ixold, at, changes[i].a-1, input[0], mode == 'u' ? " " : " ");
- fetch(ixold, changes[i].a, changes[i].b, input[0], mode == 'u' ? "-" : "- ");
- fetch(ixnew, changes[i].c, changes[i].d, input[1], mode == 'u' ? "+" : "+ ");
- at = changes[i].b+1;
+ fetch(df, df->ixold, at, df->changes[i].a-1, df->input[0], mode == 'u' ? " " : " ");
+ fetch(df, df->ixold, df->changes[i].a, df->changes[i].b, df->input[0], mode == 'u' ? "-" : "- ");
+ fetch(df, df->ixnew, df->changes[i].c, df->changes[i].d, df->input[1], mode == 'u' ? "+" : "+ ");
+ at = df->changes[i].b+1;
}
- fetch(ixold, at, b, input[0], mode == 'u' ? " " : " ");
+ fetch(df, df->ixold, at, b, df->input[0], mode == 'u' ? " " : " ");
}
- nchanges = 0;
+ df->nchanges = 0;
}
--- a/sys/src/cmd/diff/diffreg.c
+++ b/sys/src/cmd/diff/diffreg.c
@@ -66,30 +66,7 @@
* 3*(number of k-candidates installed), typically about
* 6n words for files of length n.
*/
-typedef struct Cand Cand;
-struct Cand {
- int x;
- int y;
- int pred;
-};
-
-Cand cand;
-Line *file[2], line;
-int len[2];
-int binary;
-Line *sfile[2]; /*shortened by pruning common prefix and suffix*/
-int slen[2];
-int pref, suff; /*length of prefix and suffix*/
-int *class; /*will be overlaid on file[0]*/
-int *member; /*will be overlaid on file[1]*/
-int *klist; /*will be overlaid on file[0] after class*/
-Cand *clist; /* merely a free storage pot for candidates */
-int clen;
-int *J; /*will be overlaid on class*/
-long *ixold; /*will be overlaid on klist*/
-long *ixnew; /*will be overlaid on file[1]*/
-
static void
sort(Line *a, int n) /*shellsort CACM #201*/
{
@@ -137,21 +114,21 @@
}
static void
-prune(void)
+prune(Diff *d)
{
int i,j;
- for(pref=0;pref<len[0]&&pref<len[1]&&
- file[0][pref+1].value==file[1][pref+1].value;
- pref++ ) ;
- for(suff=0;suff<len[0]-pref&&suff<len[1]-pref&&
- file[0][len[0]-suff].value==file[1][len[1]-suff].value;
- suff++) ;
+ for(d->pref = 0; d->pref < d->len[0] && d->pref < d->len[1] &&
+ d->file[0][d->pref+1].value == d->file[1][d->pref+1].value;
+ d->pref++) ;
+ for(d->suff=0; d->suff < d->len[0] - d->pref && d->suff < d->len[1] - d->pref &&
+ d->file[0][d->len[0] - d->suff].value == d->file[1][d->len[1] - d->suff].value;
+ d->suff++) ;
for(j=0;j<2;j++) {
- sfile[j] = file[j]+pref;
- slen[j] = len[j]-pref-suff;
- for(i=0;i<=slen[j];i++)
- sfile[j][i].serial = i;
+ d->sfile[j] = d->file[j]+d->pref;
+ d->slen[j] = d->len[j]-d->pref-d->suff;
+ for(i=0;i<=d->slen[j];i++)
+ d->sfile[j][i].serial = i;
}
}
@@ -184,30 +161,30 @@
}
static int
-newcand(int x, int y, int pred)
+newcand(Diff *d, int x, int y, int pred)
{
Cand *q;
- clist = erealloc(clist, (clen+1)*sizeof(Cand));
- q = clist + clen;
+ d->clist = erealloc(d->clist, (d->clen+1)*sizeof(Cand));
+ q = d->clist + d->clen;
q->x = x;
q->y = y;
q->pred = pred;
- return clen++;
+ return d->clen++;
}
static int
-search(int *c, int k, int y)
+search(Diff *d, int *c, int k, int y)
{
int i, j, l;
int t;
- if(clist[c[k]].y < y) /*quick look for typical case*/
+ if(d->clist[c[k]].y < y) /*quick look for typical case*/
return k+1;
i = 0;
j = k+1;
while((l=(i+j)/2) > i) {
- t = clist[c[l]].y;
+ t = d->clist[c[l]].y;
if(t > y)
j = l;
else if(t < y)
@@ -219,7 +196,7 @@
}
static int
-stone(int *a, int n, int *b, int *c)
+stone(Diff *d, int *a, int n, int *b, int *c)
{
int i, k,y;
int j, l;
@@ -227,7 +204,7 @@
int oldl;
k = 0;
- c[0] = newcand(0,0,0);
+ c[0] = newcand(d, 0, 0, 0);
for(i=1; i<=n; i++) {
j = a[i];
if(j==0)
@@ -236,20 +213,20 @@
oldl = 0;
oldc = c[0];
do {
- if(y <= clist[oldc].y)
+ if(y <= d->clist[oldc].y)
continue;
- l = search(c, k, y);
+ l = search(d, c, k, y);
if(l!=oldl+1)
oldc = c[l-1];
if(l<=k) {
- if(clist[c[l]].y <= y)
+ if(d->clist[c[l]].y <= y)
continue;
tc = c[l];
- c[l] = newcand(i,y,oldc);
+ c[l] = newcand(d, i, y, oldc);
oldc = tc;
oldl = l;
} else {
- c[l] = newcand(i,y,oldc);
+ c[l] = newcand(d, i,y,oldc);
k++;
break;
}
@@ -259,61 +236,23 @@
}
static void
-unravel(int p)
+unravel(Diff *d, int p)
{
int i;
Cand *q;
- for(i=0; i<=len[0]; i++) {
- if (i <= pref)
- J[i] = i;
- else if (i > len[0]-suff)
- J[i] = i+len[1]-len[0];
+ for(i=0; i<=d->len[0]; i++) {
+ if (i <= d->pref)
+ d->J[i] = i;
+ else if (i > d->len[0]-d->suff)
+ d->J[i] = i+d->len[1] - d->len[0];
else
- J[i] = 0;
+ d->J[i] = 0;
}
- for(q=clist+p;q->y!=0;q=clist+q->pred)
- J[q->x+pref] = q->y+pref;
+ for(q=d->clist+p; q->y != 0; q= d->clist + q->pred)
+ d->J[q->x+d->pref] = q->y+d->pref;
}
-static void
-output(void)
-{
- int m, i0, i1, j0, j1;
-
- m = len[0];
- J[0] = 0;
- J[m+1] = len[1]+1;
- if (mode != 'e') {
- for (i0 = 1; i0 <= m; i0 = i1+1) {
- while (i0 <= m && J[i0] == J[i0-1]+1)
- i0++;
- j0 = J[i0-1]+1;
- i1 = i0-1;
- while (i1 < m && J[i1+1] == 0)
- i1++;
- j1 = J[i1+1]-1;
- J[i1] = j1;
- change(i0, i1, j0, j1);
- }
- } else {
- for (i0 = m; i0 >= 1; i0 = i1-1) {
- while (i0 >= 1 && J[i0] == J[i0+1]-1 && J[i0])
- i0--;
- j0 = J[i0+1]-1;
- i1 = i0+1;
- while (i1 > 1 && J[i1-1] == 0)
- i1--;
- j1 = J[i1-1]+1;
- J[i1] = j1;
- change(i1 , i0, j1, j0);
- }
- }
- if (m == 0)
- change(1, 0, 1, len[1]);
- flushchanges();
-}
-
#define BUF 4096
static int
cmp(Biobuf* b1, Biobuf* b2)
@@ -361,21 +300,20 @@
}
void
-diffreg(char *f, char *fo, char *t, char *to)
+calcdiff(Diff *d, char *f, char *fo, char *t, char *to)
{
Biobuf *b0, *b1;
int k;
- binary = 0;
- b0 = prepare(0, f, fo);
+ b0 = prepare(d, 0, f, fo);
if (!b0)
return;
- b1 = prepare(1, t, to);
+ b1 = prepare(d, 1, t, to);
if (!b1) {
Bterm(b0);
return;
}
- if (binary){
+ if (d->binary){
// could use b0 and b1 but this is simpler.
if (cmp(b0, b1))
print("binary files %s %s differ\n", f, t);
@@ -383,38 +321,91 @@
Bterm(b1);
return;
}
- clen = 0;
- prune();
- sort(sfile[0], slen[0]);
- sort(sfile[1], slen[1]);
+ d->clen = 0;
+ prune(d);
+ sort(d->sfile[0], d->slen[0]);
+ sort(d->sfile[1], d->slen[1]);
- member = (int *)file[1];
- equiv(sfile[0], slen[0], sfile[1], slen[1], member);
- member = erealloc(member, (slen[1]+2)*sizeof(int));
+ d->member = (int *)d->file[1];
+ equiv(d->sfile[0], d->slen[0], d->sfile[1], d->slen[1], d->member);
+ d->member = erealloc(d->member, (d->slen[1]+2)*sizeof(int));
- class = (int *)file[0];
- unsort(sfile[0], slen[0], class);
- class = erealloc(class, (slen[0]+2)*sizeof(int));
+ d->class = (int *)d->file[0];
+ unsort(d->sfile[0], d->slen[0], d->class);
+ d->class = erealloc(d->class, (d->slen[0]+2)*sizeof(int));
- klist = emalloc((slen[0]+2)*sizeof(int));
- clist = emalloc(sizeof(Cand));
- k = stone(class, slen[0], member, klist);
- free(member);
- free(class);
+ d->klist = emalloc((d->slen[0]+2)*sizeof(int));
+ d->clist = emalloc(sizeof(Cand));
+ k = stone(d, d->class, d->slen[0], d->member, d->klist);
+ free(d->member);
+ free(d->class);
- J = emalloc((len[0]+2)*sizeof(int));
- unravel(klist[k]);
- free(clist);
- free(klist);
+ d->J = emalloc((d->len[0]+2)*sizeof(int));
+ unravel(d, d->klist[k]);
+ free(d->clist);
+ free(d->klist);
- ixold = emalloc((len[0]+2)*sizeof(long));
- ixnew = emalloc((len[1]+2)*sizeof(long));
+ d->ixold = emalloc((d->len[0]+2)*sizeof(long));
+ d->ixnew = emalloc((d->len[1]+2)*sizeof(long));
Bseek(b0, 0, 0); Bseek(b1, 0, 0);
- check(b0, b1);
- output();
- free(J);
- free(ixold);
- free(ixnew);
- Bterm(b0);
- Bterm(b1);
+ check(d, b0, b1);
+}
+
+static void
+output(Diff *d)
+{
+ int m, i0, i1, j0, j1;
+
+ m = d->len[0];
+ d->J[0] = 0;
+ d->J[m+1] = d->len[1]+1;
+ if (mode != 'e') {
+ for (i0 = 1; i0 <= m; i0 = i1+1) {
+ while (i0 <= m && d->J[i0] == d->J[i0-1]+1)
+ i0++;
+ j0 = d->J[i0-1]+1;
+ i1 = i0-1;
+ while (i1 < m && d->J[i1+1] == 0)
+ i1++;
+ j1 = d->J[i1+1]-1;
+ d->J[i1] = j1;
+ change(d, i0, i1, j0, j1);
+ }
+ } else {
+ for (i0 = m; i0 >= 1; i0 = i1-1) {
+ while (i0 >= 1 && d->J[i0] == d->J[i0+1]-1 && d->J[i0])
+ i0--;
+ j0 = d->J[i0+1]-1;
+ i1 = i0+1;
+ while (i1 > 1 && d->J[i1-1] == 0)
+ i1--;
+ j1 = d->J[i1-1]+1;
+ d->J[i1] = j1;
+ change(d, i1 , i0, j1, j0);
+ }
+ }
+ if (m == 0)
+ change(d, 1, 0, 1, d->len[1]);
+ flushchanges(d);
+}
+
+void
+diffreg(char *f, char *fo, char *t, char *to)
+{
+ Diff d;
+
+ memset(&d, 0, sizeof(d));
+ calcdiff(&d, f, fo, t, to);
+ output(&d);
+ freediff(&d);
+}
+
+void
+freediff(Diff *d)
+{
+ Bterm(d->input[0]);
+ Bterm(d->input[1]);
+ free(d->J);
+ free(d->ixold);
+ free(d->ixnew);
}
--- /dev/null
+++ b/sys/src/cmd/diff/merge3.c
@@ -1,0 +1,169 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include "diff.h"
+
+static int
+changecmp(void *a, void *b)
+{
+ return ((Change*)a)->a - ((Change*)b)->a;
+}
+
+static void
+addchange(Diff *df, int a, int b, int c, int d)
+{
+ Change *ch;
+
+ if (a > b && c > d)
+ return;
+ if(df->nchanges%1024 == 0)
+ df->changes = erealloc(df->changes, (df->nchanges+1024)*sizeof(df->changes[0]));
+ ch = &df->changes[df->nchanges++];
+ ch->a = a;
+ ch->b = b;
+ ch->c = c;
+ ch->d = d;
+}
+
+static void
+collect(Diff *d)
+{
+ int m, i0, i1, j0, j1;
+
+ m = d->len[0];
+ d->J[0] = 0;
+ d->J[m+1] = d->len[1]+1;
+ for (i0 = m; i0 >= 1; i0 = i1-1) {
+ while (i0 >= 1 && d->J[i0] == d->J[i0+1]-1 && d->J[i0])
+ i0--;
+ j0 = d->J[i0+1]-1;
+ i1 = i0+1;
+ while (i1 > 1 && d->J[i1-1] == 0)
+ i1--;
+ j1 = d->J[i1-1]+1;
+ d->J[i1] = j1;
+ addchange(d, i1 , i0, j1, j0);
+ }
+ if (m == 0)
+ change(d, 1, 0, 1, d->len[1]);
+ qsort(d->changes, d->nchanges, sizeof(Change), changecmp);
+}
+
+static int
+overlaps(Change *l, Change *r)
+{
+ if(l == nil || r == nil)
+ return 0;
+ if(l->a <= r->a)
+ return l->b >= r->a;
+ else
+ return r->b >= l->a;
+}
+
+char*
+merge(Diff *l, Diff *r)
+{
+ int il, ir, x, y, δ;
+ Change *lc, *rc;
+ char *status;
+ vlong ln;
+
+ il = 0;
+ ir = 0;
+ ln = 0;
+ status = nil;
+ collect(l);
+ collect(r);
+ while(il < l->nchanges || ir < r->nchanges){
+ lc = nil;
+ rc = nil;
+ if(il < l->nchanges)
+ lc = &l->changes[il];
+ if(ir < r->nchanges)
+ rc = &r->changes[ir];
+ if(overlaps(lc, rc)){
+ /*
+ * align the edges of the chunks
+ */
+ if(lc->a < rc->a){
+ x = lc->c;
+ δ = rc->a - lc->a;
+ rc->a -= δ;
+ rc->c -= δ;
+ }else{
+ x = rc->c;
+ δ = lc->a - rc->a;
+ lc->a -= δ;
+ lc->c -= δ;
+ }
+ if(lc->b > rc->b){
+ y = lc->d;
+ δ = lc->b - rc->b;
+ rc->b += δ;
+ rc->d += δ;
+ }else{
+ y = rc->d;
+ δ = rc->b - lc->b;
+ lc->b += δ;
+ lc->d += δ;
+ }
+ fetch(l, l->ixold, ln, x-1, l->input[0], "");
+ Bprint(&stdout, "<<<<<<<<<< %s\n", l->file2);
+ fetch(l, l->ixnew, lc->c, lc->d, l->input[1], "");
+ Bprint(&stdout, "========== original\n");
+ fetch(l, l->ixold, x, y, l->input[0], "");
+ Bprint(&stdout, "========== %s\n", r->file2);
+ fetch(r, r->ixnew, rc->c, rc->d, r->input[1], "");
+ Bprint(&stdout, ">>>>>>>>>>\n");
+ ln = y+1;
+ il++;
+ ir++;
+ status = "conflict";
+ }else if(rc == nil || (lc != nil && lc->a < rc->a)){
+ fetch(l, l->ixold, ln, lc->a-1, l->input[0], "");
+ fetch(l, l->ixnew, lc->c, lc->d, l->input[1], "");
+ ln = lc->b+1;
+ il++;
+ }else if(lc == nil || (rc != nil && rc->a < lc->a)){
+ fetch(l, l->ixold, ln, rc->a-1, l->input[0], "");
+ fetch(r, r->ixnew, rc->c, rc->d, r->input[1], "");
+ ln = rc->b+1;
+ ir++;
+ }else
+ abort();
+ }
+ if(ln < l->len[0])
+ fetch(l, l->ixold, ln, l->len[0], l->input[0], "");
+ return status;
+}
+
+void
+usage(void)
+{
+ fprint(2, "usage: %s theirs base ours\n", argv0);
+ exits("usage");
+}
+
+void
+main(int argc, char **argv)
+{
+ Diff l, r;
+ char *x;
+
+ ARGBEGIN{
+ default:
+ usage();
+ }ARGEND;
+
+ if(argc != 3)
+ usage();
+ Binit(&stdout, 1, OWRITE);
+ memset(&l, 0, sizeof(l));
+ memset(&r, 0, sizeof(r));
+ calcdiff(&l, argv[1], argv[1], argv[0], argv[0]);
+ calcdiff(&r, argv[1], argv[1], argv[2], argv[2]);
+ x = merge(&l, &r);
+ freediff(&l);
+ freediff(&r);
+ exits(x);
+}
--- a/sys/src/cmd/diff/mkfile
+++ b/sys/src/cmd/diff/mkfile
@@ -1,13 +1,13 @@
< /$objtype/mkfile
-TARG=diff
+TARG=diff merge3
OFILES=\
diffdir.$O\
diffio.$O\
diffreg.$O\
- main.$O\
+ util.$O
HFILES=diff.h
BIN=/$objtype/bin
-</sys/src/cmd/mkone
+</sys/src/cmd/mkmany
--- /dev/null
+++ b/sys/src/cmd/diff/test/diff-t10.1
@@ -1,0 +1,1 @@
+a line of text
--- /dev/null
+++ b/sys/src/cmd/diff/test/diff-t10.2
@@ -1,0 +1,1 @@
+Another line of text
--- /dev/null
+++ b/sys/src/cmd/diff/test/diff-t10.expected
@@ -1,0 +1,5 @@
+--- diff-t10.1
++++ diff-t10.2
+@@ -1 +1 @@
+-a line of text
++Another line of text
--- /dev/null
+++ b/sys/src/cmd/diff/test/diff-t11.1
@@ -1,0 +1,1003 @@
+.\" $OpenBSD: t11.1,v 1.2 2007/11/27 16:22:12 martynas Exp $
+.\" $NetBSD: ed.1,v 1.13 1995/03/21 09:04:38 cgd Exp $
+.\"
+.TH ED 1 "21 May 1993"
+.SH NAME
+.\" ed, red \- text editor
+ed \- text editor
+.SH SYNOPSIS
+ed [-] [-sx] [-p \fIstring\fR] [\fIfile\fR]
+.\" .LP
+.\" red [-] [-sx] [-p \fIstring\fR] [\fIfile\fR]
+.SH DESCRIPTION
+.B ed
+is a line-oriented text editor.
+It is used to create, display, modify and otherwise manipulate text
+files.
+.\" .B red
+.\" is a restricted
+.\" .BR ed :
+.\" it can only edit files in the current
+.\" directory and cannot execute shell commands.
+
+If invoked with a
+.I file
+argument, then a copy of
+.I file
+is read into the editor's buffer.
+Changes are made to this copy and not directly to
+.I file
+itself.
+Upon quitting
+.BR ed ,
+any changes not explicitly saved with a
+.I `w'
+command are lost.
+
+Editing is done in two distinct modes:
+.I command
+and
+.IR input .
+When first invoked,
+.B ed
+is in command mode.
+In this mode commands are read from the standard input and
+executed to manipulate the contents of the editor buffer.
+A typical command might look like:
+.sp
+.RS
+,s/\fIold\fR/\fInew\fR/g
+.RE
+.sp
+which replaces all occurrences of the string
+.I old
+with
+.IR new .
+
+When an input command, such as
+.I `a'
+(append),
+.I `i'
+(insert) or
+.I `c'
+(change), is given,
+.B ed
+enters input mode. This is the primary means
+of adding text to a file.
+In this mode, no commands are available;
+instead, the standard input is written
+directly to the editor buffer. Lines consist of text up to and
+including a
+.IR newline
+character.
+Input mode is terminated by
+entering a single period (\fI.\fR) on a line.
+
+All
+.B ed
+commands operate on whole lines or ranges of lines; e.g.,
+the
+.I `d'
+command deletes lines; the
+.I `m'
+command moves lines, and so on.
+It is possible to modify only a portion of a line by means of replacement,
+as in the example above. However even here, the
+.I `s'
+command is applied to whole lines at a time.
+
+In general,
+.B ed
+commands consist of zero or more line addresses, followed by a single
+character command and possibly additional parameters; i.e.,
+commands have the structure:
+.sp
+.RS
+.I [address [,address]]command[parameters]
+.RE
+.sp
+The address(es) indicate the line or range of lines to be affected by the
+command. If fewer addresses are given than the command accepts, then
+default addresses are supplied.
+
+.SS OPTIONS
+.TP 8
+-s
+Suppresses diagnostics. This should be used if
+.BR ed 's
+standard input is from a script.
+
+.TP 8
+-x
+Prompts for an encryption key to be used in subsequent reads and writes
+(see the
+.I `x'
+command).
+
+.TP 8
+.RI \-p \ string
+Specifies a command prompt. This may be toggled on and off with the
+.I `P'
+command.
+
+.TP 8
+.I file
+Specifies the name of a file to read. If
+.I file
+is prefixed with a
+bang (!), then it is interpreted as a shell command. In this case,
+what is read is
+the standard output of
+.I file
+executed via
+.IR sh (1).
+To read a file whose name begins with a bang, prefix the
+name with a backslash (\\).
+The default filename is set to
+.I file
+only if it is not prefixed with a bang.
+
+.SS LINE ADDRESSING
+An address represents the number of a line in the buffer.
+.B ed
+maintains a
+.I current address
+which is
+typically supplied to commands as the default address when none is specified.
+When a file is first read, the current address is set to the last line
+of the file. In general, the current address is set to the last line
+affected by a command.
+
+A line address is
+constructed from one of the bases in the list below, optionally followed
+by a numeric offset. The offset may include any combination
+of digits, operators (i.e.,
+.IR + ,
+.I -
+and
+.IR ^ )
+and whitespace.
+Addresses are read from left to right, and their values are computed
+relative to the current address.
+
+One exception to the rule that addresses represent line numbers is the
+address
+.I 0
+(zero).
+This means "before the first line,"
+and is legal wherever it makes sense.
+
+An address range is two addresses separated either by a comma or
+semi-colon. The value of the first address in a range cannot exceed the
+value of the second. If only one address is given in a range, then
+the second address is set to the given address. If an
+.IR n- tuple
+of addresses is given where
+.I n > 2,
+then the corresponding range is determined by the last two addresses in
+the
+.IR n- tuple.
+If only one address is expected, then the last address is used.
+
+Each address in a comma-delimited range is interpreted relative to the
+current address. In a semi-colon-delimited range, the first address is
+used to set the current address, and the second address is interpreted
+relative to the first.
+
+
+The following address symbols are recognized.
+
+.TP 8
+\&.
+The current line (address) in the buffer.
+
+.TP 8
+$
+The last line in the buffer.
+
+.TP 8
+n
+The
+.IR n th,
+line in the buffer
+where
+.I n
+is a number in the range
+.I [0,$].
+
+.TP 8
+- or ^
+The previous line.
+This is equivalent to
+.I -1
+and may be repeated with cumulative effect.
+
+.TP 8
+-\fIn\fR or ^\fIn\fR
+The
+.IR n th
+previous line, where
+.I n
+is a non-negative number.
+
+.TP 8
++
+The
+next line.
+This is equivalent to
+.I +1
+and may be repeated with cumulative effect.
+
+.TP 8
++\fIn\fR or whitespace\fIn\fR
+The
+.IR n th
+next line, where
+.I n
+is a non-negative number.
+.I whitespace
+followed by a number
+.I n
+is interpreted as
+.IR +n .
+
+.TP 8
+, \fRor\fB %
+The first through last lines in the buffer. This is equivalent to
+the address range
+.I 1,$.
+
+.TP 8
+;
+The
+current through last lines in the buffer. This is equivalent to
+the address range
+.I .,$.
+
+.TP 8
+.RI / re/
+The
+next line containing the regular expression
+.IR re .
+The search wraps to the beginning of the buffer and continues down to the
+current line, if necessary.
+// repeats the last search.
+
+.TP 8
+.RI ? re?
+The
+previous line containing the regular expression
+.IR re .
+The search wraps to the end of the buffer and continues up to the
+current line, if necessary.
+?? repeats the last search.
+
+.TP 8
+.RI \' lc
+The
+line previously marked by a
+.I `k'
+(mark) command, where
+.I lc
+is a lower case letter.
+
+.SS REGULAR EXPRESSIONS
+Regular expressions are patterns used in selecting text.
+For example, the
+.B ed
+command
+.sp
+.RS
+g/\fIstring\fR/
+.RE
+.sp
+prints all lines containing
+.IR string .
+Regular expressions are also
+used by the
+.I `s'
+command for selecting old text to be replaced with new.
+
+In addition to a specifying string literals, regular expressions can
+represent
+classes of strings. Strings thus represented are said to be matched
+by the corresponding regular expression.
+If it is possible for a regular expression
+to match several strings in a line, then the left-most longest match is
+the one selected.
+
+The following symbols are used in constructing regular expressions:
+
+.TP 8
+c
+Any character
+.I c
+not listed below, including `{', '}', `(', `)', `<' and `>',
+matches itself.
+
+.TP 8
+\fR\e\fIc\fR
+Any backslash-escaped character
+.IR c ,
+except for `{', '}', `(', `)', `<' and `>',
+matches itself.
+
+.TP 8
+\fR.\fR
+Matches any single character.
+
+.TP 8
+.I [char-class]
+Matches any single character in
+.IR char-class .
+To include a `]'
+in
+.IR char-class ,
+it must be the first character.
+A range of characters may be specified by separating the end characters
+of the range with a `-', e.g., `a-z' specifies the lower case characters.
+The following literal expressions can also be used in
+.I char-class
+to specify sets of characters:
+.sp
+\ \ [:alnum:]\ \ [:cntrl:]\ \ [:lower:]\ \ [:space:]
+.PD 0
+\ \ [:alpha:]\ \ [:digit:]\ \ [:print:]\ \ [:upper:]
+.PD 0
+\ \ [:blank:]\ \ [:graph:]\ \ [:punct:]\ \ [:xdigit:]
+.sp
+If `-' appears as the first or last
+character of
+.IR char-class ,
+then it matches itself.
+All other characters in
+.I char-class
+match themselves.
+.sp
+Patterns in
+.I char-class
+of the form:
+.sp
+\ \ [.\fIcol-elm\fR.] or,
+.PD 0
+\ \ [=\fIcol-elm\fR=]
+.sp
+where
+.I col-elm
+is a
+.I collating element
+are interpreted according to
+.IR locale (5)
+(not currently supported).
+See
+.IR regex (3)
+for an explanation of these constructs.
+
+.TP 8
+[^\fIchar-class\fR]
+Matches any single character, other than newline, not in
+.IR char-class .
+.IR char-class
+is defined
+as above.
+
+.TP 8
+^
+If `^' is the first character of a regular expression, then it
+anchors the regular expression to the beginning of a line.
+Otherwise, it matches itself.
+
+.TP 8
+$
+If `$' is the last character of a regular expression, it
+anchors the regular expression to the end of a line.
+Otherwise, it matches itself.
+
+.TP 8
+\fR\e<\fR
+Anchors the single character regular expression or subexpression
+immediately following it to the beginning of a word.
+(This may not be available)
+
+.TP 8
+\fR\e>\fR
+Anchors the single character regular expression or subexpression
+immediately following it to the end of a word.
+(This may not be available)
+
+.TP 8
+\fR\e(\fIre\fR\e)\fR
+Defines a subexpression
+.IR re .
+Subexpressions may be nested.
+A subsequent backreference of the form \fI`\en'\fR, where
+.I n
+is a number in the range [1,9], expands to the text matched by the
+.IR n th
+subexpression.
+For example, the regular expression `\e(.*\e)\e1' matches any string
+consisting of identical adjacent substrings.
+Subexpressions are ordered relative to
+their left delimiter.
+
+.TP 8
+*
+Matches the single character regular expression or subexpression
+immediately preceding it zero or more times. If '*' is the first
+character of a regular expression or subexpression, then it matches
+itself. The `*' operator sometimes yields unexpected results.
+For example, the regular expression `b*' matches the beginning of
+the string `abbb' (as opposed to the substring `bbb'), since a null match
+is the only left-most match.
+
+.TP 8
+\fR\e{\fIn,m\fR\e}\fR or \fR\e{\fIn,\fR\e}\fR or \fR\e{\fIn\fR\e}\fR
+Matches the single character regular expression or subexpression
+immediately preceding it at least
+.I n
+and at most
+.I m
+times.
+If
+.I m
+is omitted, then it matches at least
+.I n
+times.
+If the comma is also omitted, then it matches exactly
+.I n
+times.
+
+.LP
+Additional regular expression operators may be defined depending on the
+particular
+.IR regex (3)
+implementation.
+
+.SS COMMANDS
+All
+.B ed
+commands are single characters, though some require additonal parameters.
+If a command's parameters extend over several lines, then
+each line except for the last
+must be terminated with a backslash (\\).
+
+In general, at most one command is allowed per line.
+However, most commands accept a print suffix, which is any of
+.I `p'
+(print),
+.I `l'
+(list) ,
+or
+.I `n'
+(enumerate),
+to print the last line affected by the command.
+
+An interrupt (typically ^C) has the effect of aborting the current command
+and returning the editor to command mode.
+
+.B ed
+recognizes the following commands. The commands are shown together with
+the default address or address range supplied if none is
+specified (in parenthesis).
+
+.TP 8
+(.)a
+Appends text to the buffer after the addressed line.
+Text is entered in input mode.
+The current address is set to last line entered.
+
+.TP 8
+(.,.)c
+Changes lines in the buffer. The addressed lines are deleted
+from the buffer, and text is appended in their place.
+Text is entered in input mode.
+The current address is set to last line entered.
+
+.TP 8
+(.,.)d
+Deletes the addressed lines from the buffer.
+If there is a line after the deleted range, then the current address is set
+to this line. Otherwise the current address is set to the line
+before the deleted range.
+
+.TP 8
+.RI e \ file
+Edits
+.IR file ,
+and sets the default filename.
+If
+.I file
+is not specified, then the default filename is used.
+Any lines in the buffer are deleted before
+the new file is read.
+The current address is set to the last line read.
+
+.TP 8
+.RI e \ !command
+Edits the standard output of
+.IR `!command' ,
+(see
+.RI ! command
+below).
+The default filename is unchanged.
+Any lines in the buffer are deleted before the output of
+.I command
+is read.
+The current address is set to the last line read.
+
+.TP 8
+.RI E \ file
+Edits
+.I file
+unconditionally.
+This is similar to the
+.I e
+command,
+except that unwritten changes are discarded without warning.
+The current address is set to the last line read.
+
+.TP 8
+.RI f \ file
+Sets the default filename to
+.IR file .
+If
+.I file
+is not specified, then the default unescaped filename is printed.
+
+.TP 8
+.RI (1,$)g /re/command-list
+Applies
+.I command-list
+to each of the addressed lines matching a regular expression
+.IR re .
+The current address is set to the
+line currently matched before
+.I command-list
+is executed.
+At the end of the
+.I `g'
+command, the current address is set to the last line affected by
+.IR command-list .
+
+Each command in
+.I command-list
+must be on a separate line,
+and every line except for the last must be terminated by a backslash
+(\\).
+Any commands are allowed, except for
+.IR `g' ,
+.IR `G' ,
+.IR `v' ,
+and
+.IR `V' .
+A newline alone in
+.I command-list
+is equivalent to a
+.I `p'
+command.
+
+.TP 8
+.RI (1,$)G /re/
+Interactively edits the addressed lines matching a regular expression
+.IR re.
+For each matching line,
+the line is printed,
+the current address is set,
+and the user is prompted to enter a
+.IR command-list .
+At the end of the
+.I `G'
+command, the current address
+is set to the last line affected by (the last)
+.IR command-list .
+
+The format of
+.I command-list
+is the same as that of the
+.I `g'
+command. A newline alone acts as a null command list.
+A single `&' repeats the last non-null command list.
+
+.TP 8
+H
+Toggles the printing of error explanations.
+By default, explanations are not printed.
+It is recommended that ed scripts begin with this command to
+aid in debugging.
+
+.TP 8
+h
+Prints an explanation of the last error.
+
+.TP 8
+(.)i
+Inserts text in the buffer before the current line.
+Text is entered in input mode.
+The current address is set to the last line entered.
+
+.TP 8
+(.,.+1)j
+Joins the addressed lines. The addressed lines are
+deleted from the buffer and replaced by a single
+line containing their joined text.
+The current address is set to the resultant line.
+
+.TP 8
+.RI (.)k lc
+Marks a line with a lower case letter
+.IR lc .
+The line can then be addressed as
+.I 'lc
+(i.e., a single quote followed by
+.I lc
+) in subsequent commands. The mark is not cleared until the line is
+deleted or otherwise modified.
+
+.TP 8
+(.,.)l
+Prints the addressed lines unambiguously.
+If a single line fills for than one screen (as might be the case
+when viewing a binary file, for instance), a `--More--'
+prompt is printed on the last line.
+.B ed
+waits until the RETURN key is pressed
+before displaying the next screen.
+The current address is set to the last line
+printed.
+
+.TP 8
+(.,.)m(.)
+Moves lines in the buffer. The addressed lines are moved to after the
+right-hand destination address, which may be the address
+.IR 0
+(zero).
+The current address is set to the
+last line moved.
+
+.TP 8
+(.,.)n
+Prints the addressed lines along with
+their line numbers. The current address is set to the last line
+printed.
+
+.TP 8
+(.,.)p
+Prints the addressed lines. The current address is set to the last line
+printed.
+
+.TP 8
+P
+Toggles the command prompt on and off.
+Unless a prompt was specified by with command-line option
+\fI-p string\fR, the command prompt is by default turned off.
+
+.TP 8
+q
+Quits ed.
+
+.TP 8
+Q
+Quits ed unconditionally.
+This is similar to the
+.I q
+command,
+except that unwritten changes are discarded without warning.
+
+.TP 8
+.RI ($)r \ file
+Reads
+.I file
+to after the addressed line. If
+.I file
+is not specified, then the default
+filename is used. If there was no default filename prior to the command,
+then the default filename is set to
+.IR file .
+Otherwise, the default filename is unchanged.
+The current address is set to the last line read.
+
+.TP 8
+.RI ($)r \ !command
+Reads
+to after the addressed line
+the standard output of
+.IR `!command' ,
+(see the
+.RI ! command
+below).
+The default filename is unchanged.
+The current address is set to the last line read.
+
+.HP
+.RI (.,.)s /re/replacement/
+.PD 0
+.HP
+.RI (.,.)s /re/replacement/\fRg\fR
+.HP
+.RI (.,.)s /re/replacement/n
+.br
+Replaces text in the addressed lines
+matching a regular expression
+.I re
+with
+.IR replacement .
+By default, only the first match in each line is replaced.
+If the
+.I `g'
+(global) suffix is given, then every match to be replaced.
+The
+.I `n'
+suffix, where
+.I n
+is a postive number, causes only the
+.IR n th
+match to be replaced.
+It is an error if no substitutions are performed on any of the addressed
+lines.
+The current address is set the last line affected.
+
+.I re
+and
+.I replacement
+may be delimited by any character other than space and newline
+(see the
+.I `s'
+command below).
+If one or two of the last delimiters is omitted, then the last line
+affected is printed as though the print suffix
+.I `p'
+were specified.
+
+
+An unescaped `&' in
+.I replacement
+is replaced by the currently matched text.
+The character sequence
+\fI`\em'\fR,
+where
+.I m
+is a number in the range [1,9], is replaced by the
+.IR m th
+backreference expression of the matched text.
+If
+.I replacement
+consists of a single `%', then
+.I replacement
+from the last substitution is used.
+Newlines may be embedded in
+.I replacement
+if they are escaped with a backslash (\\).
+
+.TP 8
+(.,.)s
+Repeats the last substitution.
+This form of the
+.I `s'
+command accepts a count suffix
+.IR `n' ,
+or any combination of the characters
+.IR `r' ,
+.IR `g' ,
+and
+.IR `p' .
+If a count suffix
+.I `n'
+is given, then only the
+.IR n th
+match is replaced.
+The
+.I `r'
+suffix causes
+the regular expression of the last search to be used instead of the
+that of the last substitution.
+The
+.I `g'
+suffix toggles the global suffix of the last substitution.
+The
+.I `p'
+suffix toggles the print suffix of the last substitution
+The current address is set to the last line affected.
+
+.TP 8
+(.,.)t(.)
+Copies (i.e., transfers) the addressed lines to after the right-hand
+destination address, which may be the address
+.IR 0
+(zero).
+The current address is set to the last line
+copied.
+
+.TP 8
+u
+Undoes the last command and restores the current address
+to what it was before the command.
+The global commands
+.IR `g' ,
+.IR `G' ,
+.IR `v' ,
+and
+.IR `V' .
+are treated as a single command by undo.
+.I `u'
+is its own inverse.
+
+.TP 8
+.RI (1,$)v /pat/command-list
+Applies
+.I command-list
+to each of the addressed lines not matching a regular expression
+.IR re .
+This is similar to the
+.I `g'
+command.
+
+.TP 8
+.RI (1,$)V /re/
+Interactively edits the addressed lines not matching a regular expression
+.IR re.
+This is similar to the
+.I `G'
+command.
+
+.TP 8
+.RI (1,$)w \ file
+Writes the addressed lines to
+.IR file .
+Any previous contents of
+.I file
+is lost without warning.
+If there is no default filename, then the default filename is set to
+.IR file,
+otherwise it is unchanged. If no filename is specified, then the default
+filename is used.
+The current address is unchanged.
+
+.TP 8
+.RI (1,$)wq \ file
+Writes the addressed lines to
+.IR file ,
+and then executes a
+.I `q'
+command.
+
+.TP 8
+.RI (1,$)w \ !command
+Writes the addressed lines to the standard input of
+.IR `!command' ,
+(see the
+.RI ! command
+below).
+The default filename and current address are unchanged.
+
+.TP 8
+.RI (1,$)W \ file
+Appends the addressed lines to the end of
+.IR file .
+This is similar to the
+.I `w'
+command, expect that the previous contents of file is not clobbered.
+The current address is unchanged.
+
+.TP 8
+x
+Prompts for an encryption key which is used in subsequent reads and
+writes. If a newline alone is entered as the key, then encryption is
+turned off. Otherwise, echoing is disabled while a key is read.
+Encryption/decryption is done using the bdes(1) algorithm.
+
+.TP 8
+.RI (.+1)z n
+Scrolls
+.I n
+lines at a time starting at addressed line. If
+.I n
+is not specified, then the current window size is used.
+The current address is set to the last line printed.
+
+.TP 8
+.RI ! command
+Executes
+.I command
+via
+.IR sh (1).
+If the first character of
+.I command
+is `!', then it is replaced by text of the
+previous
+.IR `!command' .
+.B ed
+does not process
+.I command
+for backslash (\\) escapes.
+However, an unescaped
+.I `%'
+is replaced by the default filename.
+When the shell returns from execution, a `!'
+is printed to the standard output.
+The current line is unchanged.
+
+.TP 8
+($)=
+Prints the line number of the addressed line.
+
+.TP 8
+(.+1)newline
+Prints the addressed line, and sets the current address to
+that line.
+
+.SH FILES
+.TP 20
+/tmp/ed.*
+Buffer file
+.PD 0
+.TP 20
+ed.hup
+The file to which
+.B ed
+attempts to write the buffer if the terminal hangs up.
+
+.SH SEE ALSO
+
+.IR vi (1),
+.IR sed (1),
+.IR regex (3),
+.IR bdes (1),
+.IR sh (1).
+
+USD:12-13
+
+B. W. Kernighan and P. J. Plauger,
+.I Software Tools in Pascal ,
+Addison-Wesley, 1981.
+
+.SH LIMITATIONS
+.B ed
+processes
+.I file
+arguments for backslash escapes, i.e., in a filename,
+any characters preceded by a backslash (\\) are
+interpreted literally.
+
+If a text (non-binary) file is not terminated by a newline character,
+then
+.B ed
+appends one on reading/writing it. In the case of a binary file,
+.B ed
+does not append a newline on reading/writing.
+
+per line overhead: 4 ints
+
+.SH DIAGNOSTICS
+When an error occurs,
+.B ed
+prints a `?' and either returns to command mode
+or exits if its input is from a script.
+An explanation of the last error can be
+printed with the
+.I `h'
+(help) command.
+
+Since the
+.I `g'
+(global) command masks any errors from failed searches and substitutions,
+it can be used to perform conditional operations in scripts; e.g.,
+.sp
+.RS
+g/\fIold\fR/s//\fInew\fR/
+.RE
+.sp
+replaces any occurrences of
+.I old
+with
+.IR new .
+If the
+.I `u'
+(undo) command occurs in a global command list, then
+the command list is executed only once.
+
+If diagnostics are not disabled, attempting to quit
+.B ed
+or edit another file before writing a modified buffer
+results in an error.
+If the command is entered a second time, it succeeds,
+but any changes to the buffer are lost.
--- /dev/null
+++ b/sys/src/cmd/diff/test/diff-t11.2
@@ -1,0 +1,908 @@
+.\" $OpenBSD: t11.2,v 1.1 2003/07/21 20:16:21 otto Exp $
+.\"
+.Dd May 2, 1993
+.Dt ED 1
+.Os
+.Sh NAME
+.Nm ed
+.Nd text editor
+.Sh SYNOPSIS
+.Nm ed
+.Op Fl
+.Op Fl sx
+.Op Fl p Ar string
+.Op Ar file
+.Sh DESCRIPTION
+.Nm
+is a line-oriented text editor.
+It is used to create, display, modify, and otherwise manipulate text files.
+If invoked with a
+.Ar file
+argument, then a copy of
+.Ar file
+is read into the editor's buffer.
+Changes are made to this copy and not directly to
+.Ar file
+itself.
+Upon quitting
+.Nm ed ,
+any changes not explicitly saved with a
+.Em w
+command are lost.
+.Pp
+Editing is done in two distinct modes:
+.Em command
+and
+.Em input .
+When first invoked,
+.Nm
+is in command mode.
+In this mode, commands are read from the standard input and
+executed to manipulate the contents of the editor buffer.
+.Pp
+A typical command might look like:
+.Bd -literal -offset indent
+,s/old/new/g
+.Ed
+.Pp
+which replaces all occurrences of the string
+.Pa old
+with
+.Pa new .
+.Pp
+When an input command, such as
+.Em a
+(append),
+.Em i
+(insert),
+or
+.Em c
+(change) is given,
+.Nm
+enters input mode.
+This is the primary means of adding text to a file.
+In this mode, no commands are available;
+instead, the standard input is written directory to the editor buffer.
+Lines consist of text up to and including a newline character.
+Input mode is terminated by entering a single period
+.Pq Ql \&.
+on a line.
+.Pp
+All
+.Nm
+commands operate on whole lines or ranges of lines; e.g.,
+the
+.Em d
+command deletes lines; the
+.Em m
+command moves lines, and so on.
+It is possible to modify only a portion of a line by means of replacement,
+as in the example above.
+However, even here, the
+.Em s
+command is applied to whole lines at a time.
+.Pp
+In general,
+.Nm
+commands consist of zero or more line addresses, followed by a single
+character command and possibly additional parameters; i.e.,
+commands have the structure:
+.Bd -literal -offset indent
+[address [,address]]command[parameters]
+.Ed
+.Pp
+The address(es) indicate the line or range of lines to be affected by the
+command.
+If fewer addresses are given than the command accepts, then
+default addresses are supplied.
+.Pp
+The options are as follows:
+.Bl -tag -width Ds
+.It Fl
+Same as the
+.Fl s
+option (deprecated).
+.It Fl s
+Suppress diagnostics.
+This should be used if
+.Nm
+standard input is from a script.
+.Fl s
+flag.
+.It Fl x
+Prompt for an encryption key to be used in subsequent reads and writes
+(see the
+.Em x
+command).
+.It Fl p Ar string
+Specifies a command prompt.
+This may be toggled on and off with the
+.Em P
+command.
+.It Ar file
+Specifies the name of a file to read.
+If
+.Ar file
+is prefixed with a
+bang
+.Pq Ql \&! ,
+then it is interpreted as a shell command.
+In this case, what is read is the standard output of
+.Ar file
+executed via
+.Xr sh 1 .
+To read a file whose name begins with a bang, prefix the
+name with a backslash
+.Pq Ql \e .
+The default filename is set to
+.Ar file
+only if it is not prefixed with a bang.
+.El
+.Ss LINE ADDRESSING
+An address represents the number of a line in the buffer.
+.Nm
+maintains a
+.Em current address
+which is typically supplied to commands as the default address
+when none is specified.
+When a file is first read, the current address is set to the last line
+of the file.
+In general, the current address is set to the last line affected by a command.
+.Pp
+A line address is
+constructed from one of the bases in the list below, optionally followed
+by a numeric offset.
+The offset may include any combination of digits, operators (i.e.,
+.Em + ,
+.Em - ,
+and
+.Em ^ ) ,
+and whitespace.
+Addresses are read from left to right, and their values are computed
+relative to the current address.
+.Pp
+One exception to the rule that addresses represent line numbers is the
+address
+.Em 0
+(zero).
+This means
+.Dq before the first line ,
+and is legal wherever it makes sense.
+.Pp
+An address range is two addresses separated either by a comma or semi-colon.
+The value of the first address in a range cannot exceed the
+value of the second.
+If only one address is given in a range,
+then the second address is set to the given address.
+If an
+.Em n Ns No -tuple
+of addresses is given where
+.Em n > 2 ,
+then the corresponding range is determined by the last two addresses in the
+.Em n Ns No -tuple.
+If only one address is expected, then the last address is used.
+.Pp
+Each address in a comma-delimited range is interpreted relative to the
+current address.
+In a semi-colon-delimited range, the first address is
+used to set the current address, and the second address is interpreted
+relative to the first.
+.Pp
+The following address symbols are recognized:
+.Bl -tag -width Ds
+.It Em \&.
+The current line (address) in the buffer.
+.It Em $
+The last line in the buffer.
+.It Em n
+The
+.Em n Ns No th
+line in the buffer where
+.Em n
+is a number in the range
+.Em [0,$] .
+.It Em - No or Em ^
+The previous line.
+This is equivalent to
+.Em -1
+and may be repeated with cumulative effect.
+.It Em -n No or Em ^n
+The
+.Em n Ns No th
+previous line, where
+.Em n
+is a non-negative number.
+.It Em +
+The next line.
+This is equivalent to
+.Em +1
+and may be repeated with cumulative effect.
+.It Em +n
+The
+.Em n Ns No th
+next line, where
+.Em n
+is a non-negative number.
+.It Em \&, No or Em %
+The first through last lines in the buffer.
+This is equivalent to the address range
+.Em 1,$ .
+.It Em \&;
+The current through last lines in the buffer.
+This is equivalent to the address range
+.Em .,$ .
+.It Em / Ns No re Ns Em /
+The next line containing the regular expression
+.Em re .
+The search wraps to the beginning of the buffer and continues down to the
+current line, if necessary.
+.Em //
+repeats the last search.
+.It Em ? Ns No re Ns Em ?
+The previous line containing the regular expression
+.Em re .
+The search wraps to the end of the buffer and continues up to the
+current line, if necessary.
+.Em ??
+repeats the last search.
+.It Em \&\' Ns No lc
+The line previously marked by a
+.Em k
+(mark) command, where
+.Em lc
+is a lower case letter.
+.El
+.Ss REGULAR EXPRESSIONS
+Regular expressions are patterns used in selecting text.
+For example, the
+.Nm
+command
+.Bd -literal -offset indent
+g/string/
+.Ed
+.Pp
+prints all lines containing
+.Em string .
+Regular expressions are also used by the
+.Em s
+command for selecting old text to be replaced with new.
+.Pp
+In addition to a specifying string literals, regular expressions can
+represent classes of strings.
+Strings thus represented are said to be matched by the
+corresponding regular expression.
+If it is possible for a regular expression to match several strings in
+a line, then the leftmost longest match is the one selected.
+.Pp
+The following symbols are used in constructing regular expressions:
+.Bl -tag -width Dsasdfsd
+.It Em c
+Any character
+.Em c
+not listed below, including
+.Em { Ns No ,
+.Em } Ns No ,
+.Em \&( Ns No ,
+.Em \&) Ns No ,
+.Em < Ns No ,
+and
+.Em >
+matches itself.
+.It Em \ec
+Any backslash-escaped character
+.Em c Ns No ,
+except for
+.Em { Ns No ,
+.Em } Ns No ,
+.Em \&( Ns No ,
+.Em \&) Ns No ,
+.Em < Ns No , and
+.Em >
+matches itself.
+.It Em \&.
+Matches any single character.
+.It Em [char-class]
+Matches any single character in
+.Em char-class .
+To include a
+.Ql \&]
+in
+.Em char-class Ns No ,
+it must be the first character.
+A range of characters may be specified by separating the end characters
+of the range with a
+.Ql - ;
+e.g.,
+.Em a-z
+specifies the lower case characters.
+The following literal expressions can also be used in
+.Em char-class
+to specify sets of characters:
+.Pp
+.Em \ \ [:alnum:]\ \ [:cntrl:]\ \ [:lower:]\ \ [:space:]
+.Em \ \ [:alpha:]\ \ [:digit:]\ \ [:print:]\ \ [:upper:]
+.Em \ \ [:blank:]\ \ [:graph:]\ \ [:punct:]\ \ [:xdigit:]
+.Pp
+If
+.Ql -
+appears as the first or last character of
+.Em char-class Ns No ,
+then it matches itself.
+All other characters in
+.Em char-class
+match themselves.
+.Pp
+Patterns in
+.Em char-class
+of the form
+.Em [.col-elm.] No or Em [=col-elm=]
+where
+.Em col-elm
+is a collating element are interpreted according to
+.Xr locale 5
+(not currently supported).
+See
+.Xr regex 3
+for an explanation of these constructs.
+.It Em [^char-class]
+Matches any single character, other than newline, not in
+.Em char-class Ns No .
+.Em char-class
+is defined as above.
+.It Em ^
+If
+.Em ^
+is the first character of a regular expression, then it
+anchors the regular expression to the beginning of a line.
+Otherwise, it matches itself.
+.It Em $
+If
+.Em $
+is the last character of a regular expression,
+it anchors the regular expression to the end of a line.
+Otherwise, it matches itself.
+.It Em \e<
+Anchors the single character regular expression or subexpression
+immediately following it to the beginning of a word.
+(This may not be available.)
+.It Em \e>
+Anchors the single character regular expression or subexpression
+immediately following it to the end of a word.
+(This may not be available.)
+.It Em \e( Ns No re Ns Em \e)
+Defines a subexpression
+.Em re .
+Subexpressions may be nested.
+A subsequent backreference of the form
+.Em \en Ns No ,
+where
+.Em n
+is a number in the range [1,9], expands to the text matched by the
+.Em n Ns No th
+subexpression.
+For example, the regular expression
+.Em \e(.*\e)\e1
+matches any string consisting of identical adjacent substrings.
+Subexpressions are ordered relative to their left delimiter.
+.It Em *
+Matches the single character regular expression or subexpression
+immediately preceding it zero or more times.
+If
+.Em *
+is the first character of a regular expression or subexpression,
+then it matches itself.
+The
+.Em *
+operator sometimes yields unexpected results.
+For example, the regular expression
+.Em b*
+matches the beginning of the string
+.Em abbb
+(as opposed to the substring
+.Em bbb Ns No ),
+since a null match is the only leftmost match.
+.Sm off
+.It Xo Em \e{ No n,m
+.Em \e}\ \e{ No n, Em \e}\
+.Em \e{ No n Em \e}
+.Xc
+.Sm on
+Matches the single character regular expression or subexpression
+immediately preceding it at least
+.Em n
+and at most
+.Em m
+times.
+If
+.Em m
+is omitted, then it matches at least
+.Em n
+times.
+If the comma is also omitted, then it matches exactly
+.Em n
+times.
+.El
+.Pp
+Additional regular expression operators may be defined depending on the
+particular
+.Xr regex 3
+implementation.
+.Ss COMMANDS
+All
+.Nm
+commands are single characters, though some require additional parameters.
+If a command's parameters extend over several lines, then
+each line except for the last must be terminated with a backslash
+.Pq Ql \e .
+.Pp
+In general, at most one command is allowed per line.
+However, most commands accept a print suffix, which is any of
+.Em p No (print),
+.Em l No (list),
+or
+.Em n No (enumerate),
+to print the last line affected by the command.
+.Pp
+An interrupt (typically ^C) has the effect of aborting the current command
+and returning the editor to command mode.
+.Pp
+.Nm
+recognizes the following commands.
+The commands are shown together with
+the default address or address range supplied if none is
+specified (in parentheses), and other possible arguments on the right.
+.Bl -tag -width Dxxs
+.It (.) Ns Em a
+Appends text to the buffer after the addressed line.
+Text is entered in input mode.
+The current address is set to last line entered.
+.It (.,.) Ns Em c
+Changes lines in the buffer.
+The addressed lines are deleted from the buffer,
+and text is appended in their place.
+Text is entered in input mode.
+The current address is set to last line entered.
+.It (.,.) Ns Em d
+Deletes the addressed lines from the buffer.
+If there is a line after the deleted range, then the current address is set
+to this line.
+Otherwise the current address is set to the line before the deleted range.
+.It Em e No file
+Edits
+.Em file Ns No ,
+and sets the default filename.
+If
+.Em file
+is not specified, then the default filename is used.
+Any lines in the buffer are deleted before the new file is read.
+The current address is set to the last line read.
+.It Em e No !command
+Edits the standard output of
+.Em !command Ns No ,
+(see
+.Em ! No command
+below).
+The default filename is unchanged.
+Any lines in the buffer are deleted before the output of
+.Em command
+is read.
+The current address is set to the last line read.
+.It Em E No file
+Edits
+.Em file
+unconditionally.
+This is similar to the
+.Em e
+command, except that unwritten changes are discarded without warning.
+The current address is set to the last line read.
+.It Em f No file
+Sets the default filename to
+.Em file Ns No .
+If
+.Em file
+is not specified, then the default unescaped filename is printed.
+.It (1,$) Ns Em g Ns No /re/command-list
+Applies
+.Em command-list
+to each of the addressed lines matching a regular expression
+.Em re Ns No .
+The current address is set to the line currently matched before
+.Em command-list
+is executed.
+At the end of the
+.Em g
+command, the current address is set to the last line affected by
+.Em command-list Ns No .
+.Pp
+Each command in
+.Em command-list
+must be on a separate line,
+and every line except for the last must be terminated by
+.Em \e No (backslash).
+Any commands are allowed, except for
+.Em g Ns No ,
+.Em G Ns No ,
+.Em v Ns No ,
+and
+.Em V Ns No .
+A newline alone in
+.Em command-list
+is equivalent to a
+.Em p
+command.
+.It (1,$) Ns Em G Ns No /re/
+Interactively edits the addressed lines matching a regular expression
+.Em re Ns No .
+For each matching line, the line is printed, the current address is set,
+and the user is prompted to enter a
+.Em command-list Ns No .
+At the end of the
+.Em g
+command, the current address is set to the last line affected by (the last)
+.Em command-list Ns No .
+.Pp
+The format of
+.Em command-list
+is the same as that of the
+.Em g
+command.
+A newline alone acts as a null command list.
+A single
+.Em &
+repeats the last non-null command list.
+.It Em H
+Toggles the printing of error explanations.
+By default, explanations are not printed.
+It is recommended that
+.Nm
+scripts begin with this command to aid in debugging.
+.It Em h
+Prints an explanation of the last error.
+.It (.) Ns Em i
+Inserts text in the buffer before the current line.
+Text is entered in input mode.
+The current address is set to the last line entered.
+.It (.,.+1) Ns Em j
+Joins the addressed lines.
+The addressed lines are deleted from the buffer and replaced by a single
+line containing their joined text.
+The current address is set to the resultant line.
+.It (.) Ns Em klc
+Marks a line with a lower case letter
+.Em lc Ns No \&.
+The line can then be addressed as
+.Em \&'lc
+(i.e., a single quote followed by
+.Em lc Ns No )
+in subsequent commands.
+The mark is not cleared until the line is deleted or otherwise modified.
+.It (.,.) Ns Em l
+Prints the addressed lines unambiguously.
+If a single line fills more than one screen (as might be the case
+when viewing a binary file, for instance), a
+.Dq --More--
+prompt is printed on the last line.
+.Nm
+waits until the RETURN key is pressed before displaying the next screen.
+The current address is set to the last line printed.
+.It (.,.) Ns Em m Ns No (.)
+Moves lines in the buffer.
+The addressed lines are moved to after the
+right-hand destination address, which may be the address
+.Em 0
+(zero).
+The current address is set to the last line moved.
+.It (.,.) Ns Em n
+Prints the addressed lines along with their line numbers.
+The current address is set to the last line printed.
+.It (.,.) Ns Em p
+Prints the addressed lines.
+The current address is set to the last line printed.
+.It Em P
+Toggles the command prompt on and off.
+Unless a prompt was specified by with command-line option
+.Fl p Ar string Ns No ,
+the command prompt is by default turned off.
+.It Em q
+Quits
+.Nm ed .
+.It Em Q
+Quits
+.Nm
+unconditionally.
+This is similar to the
+.Em q
+command, except that unwritten changes are discarded without warning.
+.It ($) Ns Em r No file
+Reads
+.Em file
+to after the addressed line.
+If
+.Em file
+is not specified, then the default filename is used.
+If there was no default filename prior to the command,
+then the default filename is set to
+.Em file Ns No .
+Otherwise, the default filename is unchanged.
+The current address is set to the last line read.
+.It ($) Ns Em r No !command
+Reads to after the addressed line the standard output of
+.Em !command Ns No ,
+(see the
+.Em !
+command below).
+The default filename is unchanged.
+The current address is set to the last line read.
+.Sm off
+.It Xo (.,.) Em s No /re/replacement/ , \ (.,.)
+.Em s No /re/replacement/ Em g , No \ (.,.)
+.Em s No /re/replacement/ Em n
+.Xc
+.Sm on
+Replaces text in the addressed lines matching a regular expression
+.Em re
+with
+.Em replacement Ns No .
+By default, only the first match in each line is replaced.
+If the
+.Em g
+(global) suffix is given, then every match to be replaced.
+The
+.Em n
+suffix, where
+.Em n
+is a positive number, causes only the
+.Em n Ns No th
+match to be replaced.
+It is an error if no substitutions are performed on any of the addressed
+lines.
+The current address is set the last line affected.
+.Pp
+.Em re
+and
+.Em replacement
+may be delimited by any character other than space and newline
+(see the
+.Em s
+command below).
+If one or two of the last delimiters is omitted, then the last line
+affected is printed as though the print suffix
+.Em p
+were specified.
+.Pp
+An unescaped
+.Ql \e
+in
+.Em replacement
+is replaced by the currently matched text.
+The character sequence
+.Em \em Ns No ,
+where
+.Em m
+is a number in the range [1,9], is replaced by the
+.Em m Ns No th
+backreference expression of the matched text.
+If
+.Em replacement
+consists of a single
+.Ql % ,
+then
+.Em replacement
+from the last substitution is used.
+Newlines may be embedded in
+.Em replacement
+if they are escaped with a backslash
+.Pq Ql \e .
+.It (.,.) Ns Em s
+Repeats the last substitution.
+This form of the
+.Em s
+command accepts a count suffix
+.Em n Ns No ,
+or any combination of the characters
+.Em r Ns No ,
+.Em g Ns No ,
+and
+.Em p Ns No .
+If a count suffix
+.Em n
+is given, then only the
+.Em n Ns No th
+match is replaced.
+The
+.Em r
+suffix causes
+the regular expression of the last search to be used instead of the
+that of the last substitution.
+The
+.Em g
+suffix toggles the global suffix of the last substitution.
+The
+.Em p
+suffix toggles the print suffix of the last substitution
+The current address is set to the last line affected.
+.It (.,.) Ns Em t Ns No (.)
+Copies (i.e., transfers) the addressed lines to after the right-hand
+destination address, which may be the address
+.Em 0
+(zero).
+The current address is set to the last line copied.
+.It Em u
+Undoes the last command and restores the current address
+to what it was before the command.
+The global commands
+.Em g Ns No ,
+.Em G Ns No ,
+.Em v Ns No ,
+and
+.Em V Ns No .
+are treated as a single command by undo.
+.Em u
+is its own inverse.
+.It (1,$) Ns Em v Ns No /re/command-list
+Applies
+.Em command-list
+to each of the addressed lines not matching a regular expression
+.Em re Ns No .
+This is similar to the
+.Em g
+command.
+.It (1,$) Ns Em V Ns No /re/
+Interactively edits the addressed lines not matching a regular expression
+.Em re Ns No .
+This is similar to the
+.Em G
+command.
+.It (1,$) Ns Em w No file
+Writes the addressed lines to
+.Em file Ns No .
+Any previous contents of
+.Em file
+is lost without warning.
+If there is no default filename, then the default filename is set to
+.Em file Ns No ,
+otherwise it is unchanged.
+If no filename is specified, then the default filename is used.
+The current address is unchanged.
+.It (1,$) Ns Em wq No file
+Writes the addressed lines to
+.Em file Ns No ,
+and then executes a
+.Em q
+command.
+.It (1,$) Ns Em w No !command
+Writes the addressed lines to the standard input of
+.Em !command Ns No ,
+(see the
+.Em !
+command below).
+The default filename and current address are unchanged.
+.It (1,$) Ns Em W No file
+Appends the addressed lines to the end of
+.Em file Ns No .
+This is similar to the
+.Em w
+command, expect that the previous contents of file is not clobbered.
+The current address is unchanged.
+.It Em x
+Prompts for an encryption key which is used in subsequent reads and writes.
+If a newline alone is entered as the key, then encryption is turned off.
+Otherwise, echoing is disabled while a key is read.
+Encryption/decryption is done using the
+.Xr bdes 1
+algorithm.
+.It (.+1) Ns Em z Ns No n
+Scrolls
+.Em n
+lines at a time starting at addressed line.
+If
+.Em n
+is not specified, then the current window size is used.
+The current address is set to the last line printed.
+.It ($) Ns Em =
+Prints the line number of the addressed line.
+.It (.+1) Ns Em newline
+Prints the addressed line, and sets the current address to that line.
+.It Em ! Ns No command
+Executes
+.Em command
+via
+.Xr sh 1 .
+If the first character of
+.Em command
+is
+.Em ! Ns No ,
+then it is replaced by text of the previous
+.Em !command Ns No .
+.Nm
+does not process
+.Em command
+for
+.Em \e
+(backslash) escapes.
+However, an unescaped
+.Em %
+is replaced by the default filename.
+When the shell returns from execution, a
+.Em !
+is printed to the standard output.
+The current line is unchanged.
+.El
+.Sh LIMITATIONS
+.Nm
+processes
+.Em file
+arguments for backslash escapes, i.e., in a filename,
+any characters preceded by a backslash
+.Pq Ql \e
+are interpreted literally.
+.Pp
+If a text (non-binary) file is not terminated by a newline character,
+then
+.Nm
+appends one on reading/writing it.
+In the case of a binary file,
+.Nm
+does not append a newline on reading/writing.
+.Sh DIAGNOSTICS
+When an error occurs,
+.Nm
+prints a
+.Dq ?
+and either returns to command mode or exits if its input is from a script.
+An explanation of the last error can be printed with the
+.Em h
+(help) command.
+.Pp
+Since the
+.Em g
+(global) command masks any errors from failed searches and substitutions,
+it can be used to perform conditional operations in scripts; e.g.,
+.Bd -literal -offset indent
+g/old/s//new/
+.Ed
+.Pp
+replaces any occurrences of
+.Em old
+with
+.Em new Ns No .
+.Pp
+If the
+.Em u
+(undo) command occurs in a global command list, then
+the command list is executed only once.
+.Pp
+If diagnostics are not disabled, attempting to quit
+.Nm
+or edit another file before writing a modified buffer results in an error.
+If the command is entered a second time, it succeeds,
+but any changes to the buffer are lost.
+.Sh FILES
+.Bl -tag -width /tmp/ed.* -compact
+.It Pa /tmp/ed.*
+buffer file
+.It Pa ed.hup
+where
+.Nm
+attempts to write the buffer if the terminal hangs up
+.El
+.Sh SEE ALSO
+.Xr bdes 1 ,
+.Xr sed 1 ,
+.Xr sh 1 ,
+.Xr vi 1 ,
+.Xr regex 3
+.Pp
+USD:12-13
+.Rs
+.%A B. W. Kernighan
+.%A P. J. Plauger
+.%B Software Tools in Pascal
+.%O Addison-Wesley
+.%D 1981
+.Re
+.Sh HISTORY
+An
+.Nm
+command appeared in
+.At v1 .
--- /dev/null
+++ b/sys/src/cmd/diff/test/diff-t11.expected
@@ -1,0 +1,1612 @@
+--- diff-t11.1
++++ diff-t11.2
+@@ -1,1003 +1,908 @@
+-.\" $OpenBSD: t11.1,v 1.2 2007/11/27 16:22:12 martynas Exp $
+-.\" $NetBSD: ed.1,v 1.13 1995/03/21 09:04:38 cgd Exp $
++.\" $OpenBSD: t11.2,v 1.1 2003/07/21 20:16:21 otto Exp $
+ .\"
+-.TH ED 1 "21 May 1993"
+-.SH NAME
+-.\" ed, red \- text editor
+-ed \- text editor
+-.SH SYNOPSIS
+-ed [-] [-sx] [-p \fIstring\fR] [\fIfile\fR]
+-.\" .LP
+-.\" red [-] [-sx] [-p \fIstring\fR] [\fIfile\fR]
+-.SH DESCRIPTION
+-.B ed
++.Dd May 2, 1993
++.Dt ED 1
++.Os
++.Sh NAME
++.Nm ed
++.Nd text editor
++.Sh SYNOPSIS
++.Nm ed
++.Op Fl
++.Op Fl sx
++.Op Fl p Ar string
++.Op Ar file
++.Sh DESCRIPTION
++.Nm
+ is a line-oriented text editor.
+-It is used to create, display, modify and otherwise manipulate text
+-files.
+-.\" .B red
+-.\" is a restricted
+-.\" .BR ed :
+-.\" it can only edit files in the current
+-.\" directory and cannot execute shell commands.
+-
++It is used to create, display, modify, and otherwise manipulate text files.
+ If invoked with a
+-.I file
++.Ar file
+ argument, then a copy of
+-.I file
++.Ar file
+ is read into the editor's buffer.
+ Changes are made to this copy and not directly to
+-.I file
++.Ar file
+ itself.
+ Upon quitting
+-.BR ed ,
+-any changes not explicitly saved with a
+-.I `w'
++.Nm ed ,
++any changes not explicitly saved with a
++.Em w
+ command are lost.
+-
++.Pp
+ Editing is done in two distinct modes:
+-.I command
++.Em command
+ and
+-.IR input .
++.Em input .
+ When first invoked,
+-.B ed
++.Nm
+ is in command mode.
+-In this mode commands are read from the standard input and
++In this mode, commands are read from the standard input and
+ executed to manipulate the contents of the editor buffer.
++.Pp
+ A typical command might look like:
+-.sp
+-.RS
+-,s/\fIold\fR/\fInew\fR/g
+-.RE
+-.sp
++.Bd -literal -offset indent
++,s/old/new/g
++.Ed
++.Pp
+ which replaces all occurrences of the string
+-.I old
++.Pa old
+ with
+-.IR new .
+-
++.Pa new .
++.Pp
+ When an input command, such as
+-.I `a'
++.Em a
+ (append),
+-.I `i'
+-(insert) or
+-.I `c'
+-(change), is given,
+-.B ed
+-enters input mode. This is the primary means
+-of adding text to a file.
++.Em i
++(insert),
++or
++.Em c
++(change) is given,
++.Nm
++enters input mode.
++This is the primary means of adding text to a file.
+ In this mode, no commands are available;
+-instead, the standard input is written
+-directly to the editor buffer. Lines consist of text up to and
+-including a
+-.IR newline
+-character.
+-Input mode is terminated by
+-entering a single period (\fI.\fR) on a line.
+-
++instead, the standard input is written directory to the editor buffer.
++Lines consist of text up to and including a newline character.
++Input mode is terminated by entering a single period
++.Pq Ql \&.
++on a line.
++.Pp
+ All
+-.B ed
++.Nm
+ commands operate on whole lines or ranges of lines; e.g.,
+ the
+-.I `d'
++.Em d
+ command deletes lines; the
+-.I `m'
++.Em m
+ command moves lines, and so on.
+ It is possible to modify only a portion of a line by means of replacement,
+-as in the example above. However even here, the
+-.I `s'
++as in the example above.
++However, even here, the
++.Em s
+ command is applied to whole lines at a time.
+-
++.Pp
+ In general,
+-.B ed
++.Nm
+ commands consist of zero or more line addresses, followed by a single
+ character command and possibly additional parameters; i.e.,
+ commands have the structure:
+-.sp
+-.RS
+-.I [address [,address]]command[parameters]
+-.RE
+-.sp
++.Bd -literal -offset indent
++[address [,address]]command[parameters]
++.Ed
++.Pp
+ The address(es) indicate the line or range of lines to be affected by the
+-command. If fewer addresses are given than the command accepts, then
++command.
++If fewer addresses are given than the command accepts, then
+ default addresses are supplied.
+-
+-.SS OPTIONS
+-.TP 8
+--s
+-Suppresses diagnostics. This should be used if
+-.BR ed 's
++.Pp
++The options are as follows:
++.Bl -tag -width Ds
++.It Fl
++Same as the
++.Fl s
++option (deprecated).
++.It Fl s
++Suppress diagnostics.
++This should be used if
++.Nm
+ standard input is from a script.
+-
+-.TP 8
+--x
+-Prompts for an encryption key to be used in subsequent reads and writes
++.Fl s
++flag.
++.It Fl x
++Prompt for an encryption key to be used in subsequent reads and writes
+ (see the
+-.I `x'
++.Em x
+ command).
+-
+-.TP 8
+-.RI \-p \ string
+-Specifies a command prompt. This may be toggled on and off with the
+-.I `P'
++.It Fl p Ar string
++Specifies a command prompt.
++This may be toggled on and off with the
++.Em P
+ command.
+-
+-.TP 8
+-.I file
+-Specifies the name of a file to read. If
+-.I file
++.It Ar file
++Specifies the name of a file to read.
++If
++.Ar file
+ is prefixed with a
+-bang (!), then it is interpreted as a shell command. In this case,
+-what is read is
+-the standard output of
+-.I file
++bang
++.Pq Ql \&! ,
++then it is interpreted as a shell command.
++In this case, what is read is the standard output of
++.Ar file
+ executed via
+-.IR sh (1).
++.Xr sh 1 .
+ To read a file whose name begins with a bang, prefix the
+-name with a backslash (\\).
++name with a backslash
++.Pq Ql \e .
+ The default filename is set to
+-.I file
++.Ar file
+ only if it is not prefixed with a bang.
+-
+-.SS LINE ADDRESSING
++.El
++.Ss LINE ADDRESSING
+ An address represents the number of a line in the buffer.
+-.B ed
++.Nm
+ maintains a
+-.I current address
+-which is
+-typically supplied to commands as the default address when none is specified.
+-When a file is first read, the current address is set to the last line
+-of the file. In general, the current address is set to the last line
+-affected by a command.
+-
++.Em current address
++which is typically supplied to commands as the default address
++when none is specified.
++When a file is first read, the current address is set to the last line
++of the file.
++In general, the current address is set to the last line affected by a command.
++.Pp
+ A line address is
+ constructed from one of the bases in the list below, optionally followed
+-by a numeric offset. The offset may include any combination
+-of digits, operators (i.e.,
+-.IR + ,
+-.I -
++by a numeric offset.
++The offset may include any combination of digits, operators (i.e.,
++.Em + ,
++.Em - ,
+ and
+-.IR ^ )
++.Em ^ ) ,
+ and whitespace.
+ Addresses are read from left to right, and their values are computed
+ relative to the current address.
+-
++.Pp
+ One exception to the rule that addresses represent line numbers is the
+ address
+-.I 0
++.Em 0
+ (zero).
+-This means "before the first line,"
++This means
++.Dq before the first line ,
+ and is legal wherever it makes sense.
+-
+-An address range is two addresses separated either by a comma or
+-semi-colon. The value of the first address in a range cannot exceed the
+-value of the second. If only one address is given in a range, then
+-the second address is set to the given address. If an
+-.IR n- tuple
++.Pp
++An address range is two addresses separated either by a comma or semi-colon.
++The value of the first address in a range cannot exceed the
++value of the second.
++If only one address is given in a range,
++then the second address is set to the given address.
++If an
++.Em n Ns No -tuple
+ of addresses is given where
+-.I n > 2,
+-then the corresponding range is determined by the last two addresses in
+-the
+-.IR n- tuple.
++.Em n > 2 ,
++then the corresponding range is determined by the last two addresses in the
++.Em n Ns No -tuple.
+ If only one address is expected, then the last address is used.
+-
++.Pp
+ Each address in a comma-delimited range is interpreted relative to the
+-current address. In a semi-colon-delimited range, the first address is
++current address.
++In a semi-colon-delimited range, the first address is
+ used to set the current address, and the second address is interpreted
+ relative to the first.
+-
+-
+-The following address symbols are recognized.
+-
+-.TP 8
+-\&.
++.Pp
++The following address symbols are recognized:
++.Bl -tag -width Ds
++.It Em \&.
+ The current line (address) in the buffer.
+-
+-.TP 8
+-$
++.It Em $
+ The last line in the buffer.
+-
+-.TP 8
+-n
++.It Em n
+ The
+-.IR n th,
+-line in the buffer
+-where
+-.I n
++.Em n Ns No th
++line in the buffer where
++.Em n
+ is a number in the range
+-.I [0,$].
+-
+-.TP 8
+-- or ^
++.Em [0,$] .
++.It Em - No or Em ^
+ The previous line.
+ This is equivalent to
+-.I -1
++.Em -1
+ and may be repeated with cumulative effect.
+-
+-.TP 8
+--\fIn\fR or ^\fIn\fR
++.It Em -n No or Em ^n
+ The
+-.IR n th
++.Em n Ns No th
+ previous line, where
+-.I n
++.Em n
+ is a non-negative number.
+-
+-.TP 8
+-+
+-The
+-next line.
++.It Em +
++The next line.
+ This is equivalent to
+-.I +1
++.Em +1
+ and may be repeated with cumulative effect.
+-
+-.TP 8
+-+\fIn\fR or whitespace\fIn\fR
++.It Em +n
+ The
+-.IR n th
++.Em n Ns No th
+ next line, where
+-.I n
++.Em n
+ is a non-negative number.
+-.I whitespace
+-followed by a number
+-.I n
+-is interpreted as
+-.IR +n .
+-
+-.TP 8
+-, \fRor\fB %
+-The first through last lines in the buffer. This is equivalent to
+-the address range
+-.I 1,$.
+-
+-.TP 8
+-;
+-The
+-current through last lines in the buffer. This is equivalent to
+-the address range
+-.I .,$.
+-
+-.TP 8
+-.RI / re/
+-The
+-next line containing the regular expression
+-.IR re .
++.It Em \&, No or Em %
++The first through last lines in the buffer.
++This is equivalent to the address range
++.Em 1,$ .
++.It Em \&;
++The current through last lines in the buffer.
++This is equivalent to the address range
++.Em .,$ .
++.It Em / Ns No re Ns Em /
++The next line containing the regular expression
++.Em re .
+ The search wraps to the beginning of the buffer and continues down to the
+ current line, if necessary.
+-// repeats the last search.
+-
+-.TP 8
+-.RI ? re?
+-The
+-previous line containing the regular expression
+-.IR re .
++.Em //
++repeats the last search.
++.It Em ? Ns No re Ns Em ?
++The previous line containing the regular expression
++.Em re .
+ The search wraps to the end of the buffer and continues up to the
+ current line, if necessary.
+-?? repeats the last search.
+-
+-.TP 8
+-.RI \' lc
+-The
+-line previously marked by a
+-.I `k'
++.Em ??
++repeats the last search.
++.It Em \&\' Ns No lc
++The line previously marked by a
++.Em k
+ (mark) command, where
+-.I lc
++.Em lc
+ is a lower case letter.
+-
+-.SS REGULAR EXPRESSIONS
++.El
++.Ss REGULAR EXPRESSIONS
+ Regular expressions are patterns used in selecting text.
+ For example, the
+-.B ed
++.Nm
+ command
+-.sp
+-.RS
+-g/\fIstring\fR/
+-.RE
+-.sp
++.Bd -literal -offset indent
++g/string/
++.Ed
++.Pp
+ prints all lines containing
+-.IR string .
+-Regular expressions are also
+-used by the
+-.I `s'
++.Em string .
++Regular expressions are also used by the
++.Em s
+ command for selecting old text to be replaced with new.
+-
++.Pp
+ In addition to a specifying string literals, regular expressions can
+-represent
+-classes of strings. Strings thus represented are said to be matched
+-by the corresponding regular expression.
+-If it is possible for a regular expression
+-to match several strings in a line, then the left-most longest match is
+-the one selected.
+-
++represent classes of strings.
++Strings thus represented are said to be matched by the
++corresponding regular expression.
++If it is possible for a regular expression to match several strings in
++a line, then the leftmost longest match is the one selected.
++.Pp
+ The following symbols are used in constructing regular expressions:
+-
+-.TP 8
+-c
++.Bl -tag -width Dsasdfsd
++.It Em c
+ Any character
+-.I c
+-not listed below, including `{', '}', `(', `)', `<' and `>',
++.Em c
++not listed below, including
++.Em { Ns No ,
++.Em } Ns No ,
++.Em \&( Ns No ,
++.Em \&) Ns No ,
++.Em < Ns No ,
++and
++.Em >
+ matches itself.
+-
+-.TP 8
+-\fR\e\fIc\fR
++.It Em \ec
+ Any backslash-escaped character
+-.IR c ,
+-except for `{', '}', `(', `)', `<' and `>',
++.Em c Ns No ,
++except for
++.Em { Ns No ,
++.Em } Ns No ,
++.Em \&( Ns No ,
++.Em \&) Ns No ,
++.Em < Ns No , and
++.Em >
+ matches itself.
+-
+-.TP 8
+-\fR.\fR
++.It Em \&.
+ Matches any single character.
+-
+-.TP 8
+-.I [char-class]
++.It Em [char-class]
+ Matches any single character in
+-.IR char-class .
+-To include a `]'
++.Em char-class .
++To include a
++.Ql \&]
+ in
+-.IR char-class ,
++.Em char-class Ns No ,
+ it must be the first character.
+ A range of characters may be specified by separating the end characters
+-of the range with a `-', e.g., `a-z' specifies the lower case characters.
++of the range with a
++.Ql - ;
++e.g.,
++.Em a-z
++specifies the lower case characters.
+ The following literal expressions can also be used in
+-.I char-class
++.Em char-class
+ to specify sets of characters:
+-.sp
+-\ \ [:alnum:]\ \ [:cntrl:]\ \ [:lower:]\ \ [:space:]
+-.PD 0
+-\ \ [:alpha:]\ \ [:digit:]\ \ [:print:]\ \ [:upper:]
+-.PD 0
+-\ \ [:blank:]\ \ [:graph:]\ \ [:punct:]\ \ [:xdigit:]
+-.sp
+-If `-' appears as the first or last
+-character of
+-.IR char-class ,
++.Pp
++.Em \ \ [:alnum:]\ \ [:cntrl:]\ \ [:lower:]\ \ [:space:]
++.Em \ \ [:alpha:]\ \ [:digit:]\ \ [:print:]\ \ [:upper:]
++.Em \ \ [:blank:]\ \ [:graph:]\ \ [:punct:]\ \ [:xdigit:]
++.Pp
++If
++.Ql -
++appears as the first or last character of
++.Em char-class Ns No ,
+ then it matches itself.
+ All other characters in
+-.I char-class
++.Em char-class
+ match themselves.
+-.sp
++.Pp
+ Patterns in
+-.I char-class
+-of the form:
+-.sp
+-\ \ [.\fIcol-elm\fR.] or,
+-.PD 0
+-\ \ [=\fIcol-elm\fR=]
+-.sp
++.Em char-class
++of the form
++.Em [.col-elm.] No or Em [=col-elm=]
+ where
+-.I col-elm
+-is a
+-.I collating element
+-are interpreted according to
+-.IR locale (5)
++.Em col-elm
++is a collating element are interpreted according to
++.Xr locale 5
+ (not currently supported).
+ See
+-.IR regex (3)
++.Xr regex 3
+ for an explanation of these constructs.
+-
+-.TP 8
+-[^\fIchar-class\fR]
++.It Em [^char-class]
+ Matches any single character, other than newline, not in
+-.IR char-class .
+-.IR char-class
+-is defined
+-as above.
+-
+-.TP 8
+-^
+-If `^' is the first character of a regular expression, then it
++.Em char-class Ns No .
++.Em char-class
++is defined as above.
++.It Em ^
++If
++.Em ^
++is the first character of a regular expression, then it
+ anchors the regular expression to the beginning of a line.
+ Otherwise, it matches itself.
+-
+-.TP 8
+-$
+-If `$' is the last character of a regular expression, it
+-anchors the regular expression to the end of a line.
++.It Em $
++If
++.Em $
++is the last character of a regular expression,
++it anchors the regular expression to the end of a line.
+ Otherwise, it matches itself.
+-
+-.TP 8
+-\fR\e<\fR
++.It Em \e<
+ Anchors the single character regular expression or subexpression
+ immediately following it to the beginning of a word.
+-(This may not be available)
+-
+-.TP 8
+-\fR\e>\fR
++(This may not be available.)
++.It Em \e>
+ Anchors the single character regular expression or subexpression
+ immediately following it to the end of a word.
+-(This may not be available)
+-
+-.TP 8
+-\fR\e(\fIre\fR\e)\fR
++(This may not be available.)
++.It Em \e( Ns No re Ns Em \e)
+ Defines a subexpression
+-.IR re .
++.Em re .
+ Subexpressions may be nested.
+-A subsequent backreference of the form \fI`\en'\fR, where
+-.I n
++A subsequent backreference of the form
++.Em \en Ns No ,
++where
++.Em n
+ is a number in the range [1,9], expands to the text matched by the
+-.IR n th
++.Em n Ns No th
+ subexpression.
+-For example, the regular expression `\e(.*\e)\e1' matches any string
+-consisting of identical adjacent substrings.
+-Subexpressions are ordered relative to
+-their left delimiter.
+-
+-.TP 8
+-*
++For example, the regular expression
++.Em \e(.*\e)\e1
++matches any string consisting of identical adjacent substrings.
++Subexpressions are ordered relative to their left delimiter.
++.It Em *
+ Matches the single character regular expression or subexpression
+-immediately preceding it zero or more times. If '*' is the first
+-character of a regular expression or subexpression, then it matches
+-itself. The `*' operator sometimes yields unexpected results.
+-For example, the regular expression `b*' matches the beginning of
+-the string `abbb' (as opposed to the substring `bbb'), since a null match
+-is the only left-most match.
+-
+-.TP 8
+-\fR\e{\fIn,m\fR\e}\fR or \fR\e{\fIn,\fR\e}\fR or \fR\e{\fIn\fR\e}\fR
++immediately preceding it zero or more times.
++If
++.Em *
++is the first character of a regular expression or subexpression,
++then it matches itself.
++The
++.Em *
++operator sometimes yields unexpected results.
++For example, the regular expression
++.Em b*
++matches the beginning of the string
++.Em abbb
++(as opposed to the substring
++.Em bbb Ns No ),
++since a null match is the only leftmost match.
++.Sm off
++.It Xo Em \e{ No n,m
++.Em \e}\ \e{ No n, Em \e}\
++.Em \e{ No n Em \e}
++.Xc
++.Sm on
+ Matches the single character regular expression or subexpression
+ immediately preceding it at least
+-.I n
++.Em n
+ and at most
+-.I m
++.Em m
+ times.
+ If
+-.I m
++.Em m
+ is omitted, then it matches at least
+-.I n
++.Em n
+ times.
+ If the comma is also omitted, then it matches exactly
+-.I n
++.Em n
+ times.
+-
+-.LP
++.El
++.Pp
+ Additional regular expression operators may be defined depending on the
+ particular
+-.IR regex (3)
++.Xr regex 3
+ implementation.
+-
+-.SS COMMANDS
++.Ss COMMANDS
+ All
+-.B ed
+-commands are single characters, though some require additonal parameters.
++.Nm
++commands are single characters, though some require additional parameters.
+ If a command's parameters extend over several lines, then
+-each line except for the last
+-must be terminated with a backslash (\\).
+-
++each line except for the last must be terminated with a backslash
++.Pq Ql \e .
++.Pp
+ In general, at most one command is allowed per line.
+ However, most commands accept a print suffix, which is any of
+-.I `p'
+-(print),
+-.I `l'
+-(list) ,
++.Em p No (print),
++.Em l No (list),
+ or
+-.I `n'
+-(enumerate),
++.Em n No (enumerate),
+ to print the last line affected by the command.
+-
++.Pp
+ An interrupt (typically ^C) has the effect of aborting the current command
+ and returning the editor to command mode.
+-
+-.B ed
+-recognizes the following commands. The commands are shown together with
++.Pp
++.Nm
++recognizes the following commands.
++The commands are shown together with
+ the default address or address range supplied if none is
+-specified (in parenthesis).
+-
+-.TP 8
+-(.)a
++specified (in parentheses), and other possible arguments on the right.
++.Bl -tag -width Dxxs
++.It (.) Ns Em a
+ Appends text to the buffer after the addressed line.
+ Text is entered in input mode.
+ The current address is set to last line entered.
+-
+-.TP 8
+-(.,.)c
+-Changes lines in the buffer. The addressed lines are deleted
+-from the buffer, and text is appended in their place.
++.It (.,.) Ns Em c
++Changes lines in the buffer.
++The addressed lines are deleted from the buffer,
++and text is appended in their place.
+ Text is entered in input mode.
+ The current address is set to last line entered.
+-
+-.TP 8
+-(.,.)d
++.It (.,.) Ns Em d
+ Deletes the addressed lines from the buffer.
+ If there is a line after the deleted range, then the current address is set
+-to this line. Otherwise the current address is set to the line
+-before the deleted range.
+-
+-.TP 8
+-.RI e \ file
++to this line.
++Otherwise the current address is set to the line before the deleted range.
++.It Em e No file
+ Edits
+-.IR file ,
++.Em file Ns No ,
+ and sets the default filename.
+ If
+-.I file
+-is not specified, then the default filename is used.
+-Any lines in the buffer are deleted before
+-the new file is read.
++.Em file
++is not specified, then the default filename is used.
++Any lines in the buffer are deleted before the new file is read.
+ The current address is set to the last line read.
+-
+-.TP 8
+-.RI e \ !command
++.It Em e No !command
+ Edits the standard output of
+-.IR `!command' ,
++.Em !command Ns No ,
+ (see
+-.RI ! command
++.Em ! No command
+ below).
+ The default filename is unchanged.
+ Any lines in the buffer are deleted before the output of
+-.I command
++.Em command
+ is read.
+ The current address is set to the last line read.
+-
+-.TP 8
+-.RI E \ file
++.It Em E No file
+ Edits
+-.I file
++.Em file
+ unconditionally.
+ This is similar to the
+-.I e
+-command,
+-except that unwritten changes are discarded without warning.
++.Em e
++command, except that unwritten changes are discarded without warning.
+ The current address is set to the last line read.
+-
+-.TP 8
+-.RI f \ file
++.It Em f No file
+ Sets the default filename to
+-.IR file .
++.Em file Ns No .
+ If
+-.I file
++.Em file
+ is not specified, then the default unescaped filename is printed.
+-
+-.TP 8
+-.RI (1,$)g /re/command-list
++.It (1,$) Ns Em g Ns No /re/command-list
+ Applies
+-.I command-list
++.Em command-list
+ to each of the addressed lines matching a regular expression
+-.IR re .
+-The current address is set to the
+-line currently matched before
+-.I command-list
++.Em re Ns No .
++The current address is set to the line currently matched before
++.Em command-list
+ is executed.
+ At the end of the
+-.I `g'
++.Em g
+ command, the current address is set to the last line affected by
+-.IR command-list .
+-
++.Em command-list Ns No .
++.Pp
+ Each command in
+-.I command-list
++.Em command-list
+ must be on a separate line,
+-and every line except for the last must be terminated by a backslash
+-(\\).
++and every line except for the last must be terminated by
++.Em \e No (backslash).
+ Any commands are allowed, except for
+-.IR `g' ,
+-.IR `G' ,
+-.IR `v' ,
++.Em g Ns No ,
++.Em G Ns No ,
++.Em v Ns No ,
+ and
+-.IR `V' .
++.Em V Ns No .
+ A newline alone in
+-.I command-list
+-is equivalent to a
+-.I `p'
++.Em command-list
++is equivalent to a
++.Em p
+ command.
+-
+-.TP 8
+-.RI (1,$)G /re/
++.It (1,$) Ns Em G Ns No /re/
+ Interactively edits the addressed lines matching a regular expression
+-.IR re.
+-For each matching line,
+-the line is printed,
+-the current address is set,
+-and the user is prompted to enter a
+-.IR command-list .
++.Em re Ns No .
++For each matching line, the line is printed, the current address is set,
++and the user is prompted to enter a
++.Em command-list Ns No .
+ At the end of the
+-.I `G'
+-command, the current address
+-is set to the last line affected by (the last)
+-.IR command-list .
+-
++.Em g
++command, the current address is set to the last line affected by (the last)
++.Em command-list Ns No .
++.Pp
+ The format of
+-.I command-list
++.Em command-list
+ is the same as that of the
+-.I `g'
+-command. A newline alone acts as a null command list.
+-A single `&' repeats the last non-null command list.
+-
+-.TP 8
+-H
++.Em g
++command.
++A newline alone acts as a null command list.
++A single
++.Em &
++repeats the last non-null command list.
++.It Em H
+ Toggles the printing of error explanations.
+ By default, explanations are not printed.
+-It is recommended that ed scripts begin with this command to
+-aid in debugging.
+-
+-.TP 8
+-h
++It is recommended that
++.Nm
++scripts begin with this command to aid in debugging.
++.It Em h
+ Prints an explanation of the last error.
+-
+-.TP 8
+-(.)i
++.It (.) Ns Em i
+ Inserts text in the buffer before the current line.
+ Text is entered in input mode.
+ The current address is set to the last line entered.
+-
+-.TP 8
+-(.,.+1)j
+-Joins the addressed lines. The addressed lines are
+-deleted from the buffer and replaced by a single
++.It (.,.+1) Ns Em j
++Joins the addressed lines.
++The addressed lines are deleted from the buffer and replaced by a single
+ line containing their joined text.
+ The current address is set to the resultant line.
+-
+-.TP 8
+-.RI (.)k lc
++.It (.) Ns Em klc
+ Marks a line with a lower case letter
+-.IR lc .
+-The line can then be addressed as
+-.I 'lc
++.Em lc Ns No \&.
++The line can then be addressed as
++.Em \&'lc
+ (i.e., a single quote followed by
+-.I lc
+-) in subsequent commands. The mark is not cleared until the line is
+-deleted or otherwise modified.
+-
+-.TP 8
+-(.,.)l
++.Em lc Ns No )
++in subsequent commands.
++The mark is not cleared until the line is deleted or otherwise modified.
++.It (.,.) Ns Em l
+ Prints the addressed lines unambiguously.
+-If a single line fills for than one screen (as might be the case
+-when viewing a binary file, for instance), a `--More--'
+-prompt is printed on the last line.
+-.B ed
+-waits until the RETURN key is pressed
+-before displaying the next screen.
+-The current address is set to the last line
+-printed.
+-
+-.TP 8
+-(.,.)m(.)
+-Moves lines in the buffer. The addressed lines are moved to after the
++If a single line fills more than one screen (as might be the case
++when viewing a binary file, for instance), a
++.Dq --More--
++prompt is printed on the last line.
++.Nm
++waits until the RETURN key is pressed before displaying the next screen.
++The current address is set to the last line printed.
++.It (.,.) Ns Em m Ns No (.)
++Moves lines in the buffer.
++The addressed lines are moved to after the
+ right-hand destination address, which may be the address
+-.IR 0
++.Em 0
+ (zero).
+-The current address is set to the
+-last line moved.
+-
+-.TP 8
+-(.,.)n
+-Prints the addressed lines along with
+-their line numbers. The current address is set to the last line
+-printed.
+-
+-.TP 8
+-(.,.)p
+-Prints the addressed lines. The current address is set to the last line
+-printed.
+-
+-.TP 8
+-P
++The current address is set to the last line moved.
++.It (.,.) Ns Em n
++Prints the addressed lines along with their line numbers.
++The current address is set to the last line printed.
++.It (.,.) Ns Em p
++Prints the addressed lines.
++The current address is set to the last line printed.
++.It Em P
+ Toggles the command prompt on and off.
+ Unless a prompt was specified by with command-line option
+-\fI-p string\fR, the command prompt is by default turned off.
+-
+-.TP 8
+-q
+-Quits ed.
+-
+-.TP 8
+-Q
+-Quits ed unconditionally.
++.Fl p Ar string Ns No ,
++the command prompt is by default turned off.
++.It Em q
++Quits
++.Nm ed .
++.It Em Q
++Quits
++.Nm
++unconditionally.
+ This is similar to the
+-.I q
+-command,
+-except that unwritten changes are discarded without warning.
+-
+-.TP 8
+-.RI ($)r \ file
++.Em q
++command, except that unwritten changes are discarded without warning.
++.It ($) Ns Em r No file
+ Reads
+-.I file
+-to after the addressed line. If
+-.I file
+-is not specified, then the default
+-filename is used. If there was no default filename prior to the command,
++.Em file
++to after the addressed line.
++If
++.Em file
++is not specified, then the default filename is used.
++If there was no default filename prior to the command,
+ then the default filename is set to
+-.IR file .
++.Em file Ns No .
+ Otherwise, the default filename is unchanged.
+ The current address is set to the last line read.
+-
+-.TP 8
+-.RI ($)r \ !command
+-Reads
+-to after the addressed line
+-the standard output of
+-.IR `!command' ,
++.It ($) Ns Em r No !command
++Reads to after the addressed line the standard output of
++.Em !command Ns No ,
+ (see the
+-.RI ! command
+-below).
++.Em !
++command below).
+ The default filename is unchanged.
+ The current address is set to the last line read.
+-
+-.HP
+-.RI (.,.)s /re/replacement/
+-.PD 0
+-.HP
+-.RI (.,.)s /re/replacement/\fRg\fR
+-.HP
+-.RI (.,.)s /re/replacement/n
+-.br
+-Replaces text in the addressed lines
+-matching a regular expression
+-.I re
++.Sm off
++.It Xo (.,.) Em s No /re/replacement/ , \ (.,.)
++.Em s No /re/replacement/ Em g , No \ (.,.)
++.Em s No /re/replacement/ Em n
++.Xc
++.Sm on
++Replaces text in the addressed lines matching a regular expression
++.Em re
+ with
+-.IR replacement .
++.Em replacement Ns No .
+ By default, only the first match in each line is replaced.
+ If the
+-.I `g'
++.Em g
+ (global) suffix is given, then every match to be replaced.
+ The
+-.I `n'
++.Em n
+ suffix, where
+-.I n
+-is a postive number, causes only the
+-.IR n th
++.Em n
++is a positive number, causes only the
++.Em n Ns No th
+ match to be replaced.
+ It is an error if no substitutions are performed on any of the addressed
+ lines.
+ The current address is set the last line affected.
+-
+-.I re
++.Pp
++.Em re
+ and
+-.I replacement
++.Em replacement
+ may be delimited by any character other than space and newline
+ (see the
+-.I `s'
++.Em s
+ command below).
+ If one or two of the last delimiters is omitted, then the last line
+ affected is printed as though the print suffix
+-.I `p'
++.Em p
+ were specified.
+-
+-
+-An unescaped `&' in
+-.I replacement
++.Pp
++An unescaped
++.Ql \e
++in
++.Em replacement
+ is replaced by the currently matched text.
+ The character sequence
+-\fI`\em'\fR,
++.Em \em Ns No ,
+ where
+-.I m
++.Em m
+ is a number in the range [1,9], is replaced by the
+-.IR m th
++.Em m Ns No th
+ backreference expression of the matched text.
+ If
+-.I replacement
+-consists of a single `%', then
+-.I replacement
++.Em replacement
++consists of a single
++.Ql % ,
++then
++.Em replacement
+ from the last substitution is used.
+ Newlines may be embedded in
+-.I replacement
+-if they are escaped with a backslash (\\).
+-
+-.TP 8
+-(.,.)s
++.Em replacement
++if they are escaped with a backslash
++.Pq Ql \e .
++.It (.,.) Ns Em s
+ Repeats the last substitution.
+ This form of the
+-.I `s'
++.Em s
+ command accepts a count suffix
+-.IR `n' ,
++.Em n Ns No ,
+ or any combination of the characters
+-.IR `r' ,
+-.IR `g' ,
++.Em r Ns No ,
++.Em g Ns No ,
+ and
+-.IR `p' .
++.Em p Ns No .
+ If a count suffix
+-.I `n'
++.Em n
+ is given, then only the
+-.IR n th
++.Em n Ns No th
+ match is replaced.
+ The
+-.I `r'
++.Em r
+ suffix causes
+ the regular expression of the last search to be used instead of the
+ that of the last substitution.
+ The
+-.I `g'
++.Em g
+ suffix toggles the global suffix of the last substitution.
+ The
+-.I `p'
++.Em p
+ suffix toggles the print suffix of the last substitution
+ The current address is set to the last line affected.
+-
+-.TP 8
+-(.,.)t(.)
++.It (.,.) Ns Em t Ns No (.)
+ Copies (i.e., transfers) the addressed lines to after the right-hand
+ destination address, which may be the address
+-.IR 0
++.Em 0
+ (zero).
+-The current address is set to the last line
+-copied.
+-
+-.TP 8
+-u
++The current address is set to the last line copied.
++.It Em u
+ Undoes the last command and restores the current address
+ to what it was before the command.
+ The global commands
+-.IR `g' ,
+-.IR `G' ,
+-.IR `v' ,
++.Em g Ns No ,
++.Em G Ns No ,
++.Em v Ns No ,
+ and
+-.IR `V' .
++.Em V Ns No .
+ are treated as a single command by undo.
+-.I `u'
++.Em u
+ is its own inverse.
+-
+-.TP 8
+-.RI (1,$)v /pat/command-list
++.It (1,$) Ns Em v Ns No /re/command-list
+ Applies
+-.I command-list
++.Em command-list
+ to each of the addressed lines not matching a regular expression
+-.IR re .
++.Em re Ns No .
+ This is similar to the
+-.I `g'
++.Em g
+ command.
+-
+-.TP 8
+-.RI (1,$)V /re/
++.It (1,$) Ns Em V Ns No /re/
+ Interactively edits the addressed lines not matching a regular expression
+-.IR re.
++.Em re Ns No .
+ This is similar to the
+-.I `G'
++.Em G
+ command.
+-
+-.TP 8
+-.RI (1,$)w \ file
++.It (1,$) Ns Em w No file
+ Writes the addressed lines to
+-.IR file .
++.Em file Ns No .
+ Any previous contents of
+-.I file
++.Em file
+ is lost without warning.
+ If there is no default filename, then the default filename is set to
+-.IR file,
+-otherwise it is unchanged. If no filename is specified, then the default
+-filename is used.
++.Em file Ns No ,
++otherwise it is unchanged.
++If no filename is specified, then the default filename is used.
+ The current address is unchanged.
+-
+-.TP 8
+-.RI (1,$)wq \ file
++.It (1,$) Ns Em wq No file
+ Writes the addressed lines to
+-.IR file ,
++.Em file Ns No ,
+ and then executes a
+-.I `q'
++.Em q
+ command.
+-
+-.TP 8
+-.RI (1,$)w \ !command
++.It (1,$) Ns Em w No !command
+ Writes the addressed lines to the standard input of
+-.IR `!command' ,
++.Em !command Ns No ,
+ (see the
+-.RI ! command
+-below).
++.Em !
++command below).
+ The default filename and current address are unchanged.
+-
+-.TP 8
+-.RI (1,$)W \ file
++.It (1,$) Ns Em W No file
+ Appends the addressed lines to the end of
+-.IR file .
++.Em file Ns No .
+ This is similar to the
+-.I `w'
++.Em w
+ command, expect that the previous contents of file i
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [9front] merge3: a first draft
2023-02-25 16:56 ` ori
@ 2023-03-04 20:06 ` ori
0 siblings, 0 replies; 3+ messages in thread
From: ori @ 2023-03-04 20:06 UTC (permalink / raw)
To: 9front
Quoth ori@eigenstate.org:
> Quoth ori@eigenstate.org:
> > I've been annoyed that we have to use ape/diff3 to merge
> > files for a while, so I finally sat down this weekend and
> > hacked 3-way merge capabilities into diff(1).
> >
> > This is a rough draft, but here's the current approach.
> >
> > 3 way merging operates as follows:
> >
>
> Now bugfixed, and with tests.
>
hearing no objections: pushed.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2023-02-12 23:17 [9front] merge3: a first draft ori
2023-02-25 16:56 ` ori
2023-03-04 20:06 ` ori
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