Re: [9fans] tab completion and command history in rc

[Russ Cox <rsc@swtch.com>]

> i looked at modifying rc to write commands to a history file but it
> didn't seem to fit very well. maybe a hook would be better as in

it's not hard.  perhaps you object to rc's reformatting of
what you typed?

diff -c ./exec.c h/exec.c
./exec.c:9,14 - h/exec.c:9,16
  #include "exec.h"
  #include "io.h"
  #include "fns.h"
+
+ tree *line;
  /*
   * Start executing the given code at the given pc with the given redirection
   */
./exec.c:112,118 - h/exec.c:114,120
  {
  	code bootstrap[32];
  	char num[12], *rcmain;
- 	int i;
+ 	int i, fd;
  	
  	/* needed for rcmain later */
  	putenv("PLAN9", unsharp("#9"));
./exec.c:123,128 - h/exec.c:125,132
  	if(flag['I']) flag['i'] = 0;
  	else if(flag['i']==0 && argc==1 && Isatty(0)) flag['i'] = flagset;
  	rcmain=flag['m']?flag['m'][0]:Rcmain();
+ 	if((fd = open("/tmp/history", OWRITE)) >= 0)
+ 		history=openfd(fd);
  	err=openfd(2);
  	kinit();
  	Trapinit();
./exec.c:773,778 - h/exec.c:777,788
  		}
  	}
  	else{
+ 		if(p->iflag && history && line){
+ 			char buf[30];
+ 			strcpy(buf, ctime(time(0)));
+ 			buf[28] = 0;
+ 			pfmt(history, "%s %t\n", buf, line);
+ 		}
  		ntrap = 0;	/* avoid double-interrupts during blocked writes */
  		--p->pc;	/* re-execute Xrdcmds after codebuf runs */
  		start(codebuf, 1, runq->local);
diff -c ./io.h h/io.h
./io.h:11,16 - h/io.h:11,17
  	char *bufp, *ebuf, *strp, buf[NBUF];
  };
  io *err;
+ io *history;
  io *openfd(int), *openstr(void), *opencore(char *, int);
  int emptybuf(io*);
  void pchr(io*, int);
diff -c ./rc.h h/rc.h
./rc.h:143,145 - h/rc.h:143,146
  int lastc;
  int lastword;
  int kidpid;
+ extern tree *line;
diff -c ./syn.y h/syn.y
./syn.y:21,28 - h/syn.y:21,28
  %type<tree> NOT FOR IN WHILE IF TWIDDLE BANG SUBSHELL SWITCH FN
  %type<tree> WORD REDIR DUP PIPE
  %%
- rc:				{ return 1;}
- |	line '\n'		{return !compile($1);}
+ rc:				{ line = nil; return 1;}
+ |	line '\n'		{ line = $1; return !compile($1);}
  line:	cmd
  |	cmdsa line		{$$=tree2(';', $1, $2);}
  body:	cmd