Re: [9fans] Practical issue on using rc shell

[erik quanstrom <quanstro@coraid.com>]

what i find i can't live without is a record
of the commands i've typed.  sometimes a
one-liner from last week is useful.  i use the
commands - and -- (source: /n/sources/contrib/quanstro/src/history.c)
along with the following patch to rc to make it
go.

- erik

; 9diff fns.h
/n/sources/plan9//sys/src/cmd/rc/fns.h:61,66 - fns.h:61,67
  void	start(code*, int, var*);
  int	truestatus(void);
  void	usage(char*);
+ void whistory(tree*);
  int	wordchr(int);
  void	yyerror(char*);
  int	yylex(void);
; 9diff *.y
post...
/n/sources/plan9//sys/src/cmd/rc/syn.y:12,17 - syn.y:12,28
  %{
  #include "rc.h"
  #include "fns.h"
+
+ int
+ hcompile(tree *t)
+ {
+ 	int i;
+
+ 	if(i = compile(t))
+ 		whistory(t);
+ 	return !i;
+ }
+
  %}
  %union{
  	struct tree *tree;
/n/sources/plan9//sys/src/cmd/rc/syn.y:22,28 - syn.y:33,39
  %type<tree> WORD REDIR DUP PIPE
  %%
  rc:				{ return 1;}
- |	line '\n'		{return !compile($1);}
+ |	line '\n'			{ return hcompile($1); }
  line:	cmd
  |	cmdsa line		{$$=tree2(';', $1, $2);}
  body:	cmd
; cat history.c
#include "rc.h"
#include "exec.h"
#include "fns.h"
#include "io.h"

void
whistory(tree *t){
	char* s;
	int fd, flags;
	io* o;
	var* v;

	if(!runq->iflag || !t)
		return;
	v = vlook("history");
	if(!v->val || count(v->val) != 1)
		return;
	if(v->fn)
		return;	/* fn history {echo $*>>$history_file} ? */

	s = v->val->word;
	flags = OWRITE;
	if((fd=open(s, flags))<0 && (fd=create(s, flags, DMAPPEND|0666L))<0){
		/* setvar("history", 0); */
		return;
	}

	o = openfd(fd);
	seek(fd, 0, 2);
	pfmt(o, "%t\n", t);
	closeio(o);
}