aux/getflags: name the flags

[ori@eigenstate.org]

I dislike using aux/getflags, because the flag
names aren't under my control. So I patched it:

% flagfmt='b:bullshit,s:stuff,f:dobinary binary,r res,x width'
% 6.getflags -bsflags and some args
bullshit=()
stuff=()
dobinary=()
flagr=()
flagx=()
bullshit=1
stuff=1
dobinary=(lags)
*=(and some args)
status=''

I'm not sure if this should be committed -- but the code is here:

diff -r 247ac32522a0 sys/src/cmd/aux/getflags.c
--- a/sys/src/cmd/aux/getflags.c	Wed Apr 15 18:16:22 2020 +0200
+++ b/sys/src/cmd/aux/getflags.c	Fri Apr 17 14:10:28 2020 -0700
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <libc.h>
+#include <ctype.h>
 
 void
 usage(void)
@@ -22,6 +23,21 @@
 	return nil;	
 }
 
+char*
+argname(char *p)
+{
+	Rune r;
+	int n;
+
+	while(1){
+		n = chartorune(&r, p);
+		if(!isalpharune(r) && !isdigitrune(r))
+			break;
+		p += n;
+	}
+	return p;
+}
+
 int
 countargs(char *p)
 {
@@ -39,7 +55,7 @@
 void
 main(int argc, char *argv[])
 {
-	char *flags, *p, buf[512];
+	char *flags, *p, *s, *e, buf[512];
 	int i, n;
 	Fmt fmt;
 	
@@ -55,19 +71,38 @@
 	}
 
 	fmtfdinit(&fmt, 1, buf, sizeof buf);
-	for(p=flags; p!=(char*)1; p=strchr(p, ',')+1)
-		fmtprint(&fmt, "flag%.1s=()\n", p);
+	for(p=flags; p!=(char*)1 && *p != 0; p=strchr(p, ',')+1){
+		s = e = nil;
+		if(p[1] == ':'){
+			s = p + 2;
+			e = argname(s);
+		}
+		if(s != e)
+			fmtprint(&fmt, "%.*s=()\n", (int)(e - s), s);
+		else
+			fmtprint(&fmt, "flag%.1s=()\n", p);
+	}
 	ARGBEGIN{
 	default:
 		if((p = findarg(flags, ARGC())) == nil)
 			usage();
 		p += runelen(ARGC());
+		s = p + 1;
+		e = p + 1;
+		if(*p == ':' && (e = argname(s)) != s)
+			p = e;
 		if(*p == ',' || *p == 0){
-			fmtprint(&fmt, "flag%C=1\n", ARGC());
+			if(s != e)
+				fmtprint(&fmt, "%.*s=1\n", (int)(e - s), s);
+			else
+				fmtprint(&fmt, "flag%C=1\n", ARGC());
 			break;
 		}
 		n = countargs(p);
-		fmtprint(&fmt, "flag%C=(", ARGC());
+		if(s != e)
+			fmtprint(&fmt, "%.*s=(", (int)(e - s), s);
+		else
+			fmtprint(&fmt, "flag%C=(", ARGC());
 		for(i=0; i<n; i++)
 			fmtprint(&fmt, "%s%q", i ? " " : "", EARGF(usage()));
 		fmtprint(&fmt, ")\n");
diff -r 247ac32522a0 sys/src/cmd/aux/usage.c
--- a/sys/src/cmd/aux/usage.c	Wed Apr 15 18:16:22 2020 +0200
+++ b/sys/src/cmd/aux/usage.c	Fri Apr 17 14:10:28 2020 -0700
@@ -31,6 +31,9 @@
 		single = 0;
 		for(p=flags; *p; ){
 			p += chartorune(&r, p);
+			if(*p == ':')
+				while(*p != '\0' && *p != ',' && *p != ' ')
+					p++;
 			if(*p == ',' || *p == 0){
 				if(!single){
 					fmtprint(&fmt, " [-");