Re: [9fans] print(2)'s format

[erik quanstrom <quanstro@quanstro.net>]

> Hello, this is the little story:
> I usually write scripts needing numbers padded on the left with zeros, like in '%03.0f'.  In UNIX I use printf(1), but now I'm using more and more rc scripts with P9P, and I like to use Plan9 programs to make the scripts more portable to Plan9... so I tried with seq, like '9 seq -f%03.0f $i $i' or -f%03g, getting the desired output in P9P, but discovering that in Plan9, the floating point verbs doesn't include the flag '0'.
> I'm really curious about this.  Anyone knows the reason of letting out this flag (and including it in P9P)?
>

i am not sure if there is any knock-on to this, but i think this is all that's
required.  unfortunately %06s might do some wierd things.  shouldn't
be a big issue, since that's not specified anyway,  and
	g '%0[0-9]*(\.[0-9]*)?[sq]' /sys/src
turns up nothing.

i'm considering the patch.

- erik

diff -c /n/dump/2014/0302/sys/src/libc/fmt/dofmt.c ./dofmt.c
/n/dump/2014/0302/sys/src/libc/fmt/dofmt.c:87,99 - ./dofmt.c:87,100
  int
  _fmtpad(Fmt *f, int n)
  {
- 	char *t, *s;
+ 	char *t, *s, c;
  	int i;

  	t = f->to;
  	s = f->stop;
+ 	c = f->flags&FmtZero? '0': ' ';
  	for(i = 0; i < n; i++)
- 		FMTCHAR(f, t, s, ' ');
+ 		FMTCHAR(f, t, s, c);
  	f->nfmt += t - (char *)f->to;
  	f->to = t;
  	return 0;
/n/dump/2014/0302/sys/src/libc/fmt/dofmt.c:102,114 - ./dofmt.c:103,116
  int
  _rfmtpad(Fmt *f, int n)
  {
- 	Rune *t, *s;
+ 	Rune *t, *s, r;
  	int i;

  	t = f->to;
  	s = f->stop;
+ 	r = f->flags&FmtZero? '0': ' ';
  	for(i = 0; i < n; i++)
- 		FMTRCHAR(f, t, s, ' ');
+ 		FMTRCHAR(f, t, s, r);
  	f->nfmt += t - (Rune *)f->to;
  	f->to = t;
  	return 0;
diff -c /n/dump/2014/0302/sys/src/libc/fmt/fltfmt.c ./fltfmt.c
/n/dump/2014/0302/sys/src/libc/fmt/fltfmt.c:303,309 - ./fltfmt.c:303,309
  	 * which is 341 currently.
  	 */
  	xdtoa(fmt, s, f);
- 	fmt->flags &= FmtWidth|FmtLeft;
+ 	fmt->flags &= FmtZero|FmtWidth|FmtLeft;
  	_fmtcpy(fmt, s, strlen(s), strlen(s));
  	return 0;
  }