Re: PATCH: ztrftime %. for fractions of a second in prompts

[Vin Shelton <acs@alumni.princeton.edu>]

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Dear Peter,

On my Mint 17 system, the latest code fails to compile with gcc 4.8.2:

gcc -c -I. -I../../Src -I/opt/src/zsh-2014-07-30/Src
-I/opt/src/zsh-2014-07-30/Src/Zle -I/opt/src/zsh-2014-07-30/Src/Builtins
 -DHAVE_CONFIG_H -DMODULE -Wall -Wmissing-prototypes -O2 -fPIC -o sched..o
/opt/src/zsh-2014-07-30/Src/Builtins/sched.c
/opt/src/zsh-2014-07-30/Src/Builtins/sched.c: In function ‘bin_sched’:
/opt/src/zsh-2014-07-30/Src/Builtins/sched.c:214:6: error: too few
arguments to function ‘ztrftime’
      ztrftime(tbuf, 40, "%a %b %e %k:%M:%S", tmp);
      ^
In file included from ./../../Src/zsh.mdh:62:0,
                 from ./sched.mdh:17,
                 from /opt/src/zsh-2014-07-30/Src/Builtins/sched.c:30:
./../../Src/utils.epro:80:32: note: declared here
 extern mod_import_function int ztrftime _((char*buf,int
bufsize,char*fmt,struct tm*tm,long usec));
                                ^
make[3]: *** [sched..o] Error 1
make[3]: Leaving directory `/opt/build/zsh-2014-07-30/Src/Builtins'
make[2]: *** [modules] Error 1
make[2]: Leaving directory `/opt/build/zsh-2014-07-30/Src'
make[1]: *** [modules] Error 2
make[1]: Leaving directory `/opt/build/zsh-2014-07-30/Src'
make: *** [all] Error 1

Please let me know if you need more info.

  - Vin


On Wed, Jul 30, 2014 at 3:46 AM, Peter Stephenson <p.stephenson@samsung.com>
wrote:

> I was trying to get some timings in prompts to better than a second ---
> not particularly useful in a regular shell prompt, but very useful in
> the prompts provided by e.g. the TCP functions.
>
> I was shocked! shocked! to find this appears not to be possible.
>
> I've used %. for this as it's definitely not POSIX and is very easy to
> remember.  You can specify 1 to 6 digits between the '%' and the '.'.
>
> This doesn't appear to be useful in non-prompt calls to ztrftime() since
> the fractions of a second aren't available.
>
> pws
>
>
> diff --git a/Doc/Zsh/prompt.yo b/Doc/Zsh/prompt.yo
> index eab15d2..36f351b 100644
> --- a/Doc/Zsh/prompt.yo
> +++ b/Doc/Zsh/prompt.yo
> @@ -185,6 +185,13 @@ sitem(tt(%K))(the hour of the day on the 24-hour
> clock)
>  sitem(tt(%L))(the hour of the day on the 12-hour clock)
>  endsitem()
>
> +In addition, if the system supports the POSIX tt(gettimeofday) system
> +call, tt(%.) provides decimal fractions of a second since the epoch with
> +leading zeroes.  By default three decimal places are provided, but a
> +number of digits up to 6 may be given following the tt(%); hence tt(%6.)
> +outputs microseconds.  A typical example of this is the format
> +`tt(%D{%H:%M:%S.%.})'.
> +
>  The GNU extension that a `tt(-)' between the tt(%) and the
>  format character causes a leading zero or space to be stripped
>  is handled directly by the shell for the format characters tt(d), tt(f),
> diff --git a/Src/builtin.c b/Src/builtin.c
> index 34a5296..a2a3ad7 100644
> --- a/Src/builtin.c
> +++ b/Src/builtin.c
> @@ -1731,7 +1731,7 @@ fclist(FILE *f, Options ops, zlong first, zlong last,
>             if (tdfmt != NULL) {
>                 struct tm *ltm;
>                 ltm = localtime(&ent->stim);
> -               if (ztrftime(timebuf, 256, tdfmt, ltm))
> +               if (ztrftime(timebuf, 256, tdfmt, ltm, 0L))
>                     fprintf(f, "%s  ", timebuf);
>             }
>             /* display the time taken by the command, if required */
> diff --git a/Src/prompt.c b/Src/prompt.c
> index 95a7d49..c16d781 100644
> --- a/Src/prompt.c
> +++ b/Src/prompt.c
> @@ -270,6 +270,8 @@ putpromptchar(int doprint, int endchar, unsigned int
> *txtchangep)
>      char *ss, *hostnam;
>      int t0, arg, test, sep, j, numjobs;
>      struct tm *tm;
> +    struct timezone dummy_tz;
> +    struct timeval tv;
>      time_t timet;
>      Nameddir nd;
>
> @@ -636,8 +638,8 @@ putpromptchar(int doprint, int endchar, unsigned int
> *txtchangep)
>                         tmfmt = "%l:%M%p";
>                         break;
>                     }
> -                   timet = time(NULL);
> -                   tm = localtime(&timet);
> +                   gettimeofday(&tv, &dummy_tz);
> +                   tm = localtime(&tv.tv_sec);
>                     /*
>                      * Hack because strftime won't say how
>                      * much space it actually needs.  Try to add it
> @@ -647,7 +649,7 @@ putpromptchar(int doprint, int endchar, unsigned int
> *txtchangep)
>                      */
>                     for(j = 0, t0 = strlen(tmfmt)*8; j < 3; j++, t0*=2) {
>                         addbufspc(t0);
> -                       if (ztrftime(bv->bp, t0, tmfmt, tm) >= 0)
> +                       if (ztrftime(bv->bp, t0, tmfmt, tm, tv.tv_usec) >=
> 0)
>                             break;
>                     }
>                     /* There is enough room for this because addbufspc(t0)
> diff --git a/Src/utils.c b/Src/utils.c
> index cef2abe..aa978e6 100644
> --- a/Src/utils.c
> +++ b/Src/utils.c
> @@ -2710,7 +2710,7 @@ ztrftimebuf(int *bufsizeptr, int decr)
>
>  /**/
>  mod_export int
> -ztrftime(char *buf, int bufsize, char *fmt, struct tm *tm)
> +ztrftime(char *buf, int bufsize, char *fmt, struct tm *tm, long usec)
>  {
>      int hr12;
>  #ifdef HAVE_STRFTIME
> @@ -2729,6 +2729,7 @@ ztrftime(char *buf, int bufsize, char *fmt, struct
> tm *tm)
>      while (*fmt)
>         if (*fmt == '%') {
>             int strip;
> +           int digs = 3;
>
>             fmt++;
>             if (*fmt == '-') {
> @@ -2736,6 +2737,17 @@ ztrftime(char *buf, int bufsize, char *fmt, struct
> tm *tm)
>                 fmt++;
>             } else
>                 strip = 0;
> +           if (idigit(*fmt)) {
> +               /* Digit --- only useful with . */
> +               char *dstart = fmt;
> +               char *dend = fmt+1;
> +               while (idigit(*dend))
> +                   dend++;
> +               if (*dend == '.') {
> +                   fmt = dend;
> +                   digs = atoi(dstart);
> +               }
> +           }
>             /*
>              * Assume this format will take up at least two
>              * characters.  Not always true, but if that matters
> @@ -2745,6 +2757,20 @@ ztrftime(char *buf, int bufsize, char *fmt, struct
> tm *tm)
>             if (ztrftimebuf(&bufsize, 2))
>                 return -1;
>             switch (*fmt++) {
> +           case '.':
> +               if (ztrftimebuf(&bufsize, digs))
> +                   return -1;
> +               if (digs > 6)
> +                   digs = 6;
> +               if (digs < 6) {
> +                   int trunc;
> +                   for (trunc = 5 - digs; trunc; trunc--)
> +                       usec /= 10;
> +                   usec  = (usec + 5) / 10;
> +               }
> +               sprintf(buf, "%0*ld", digs, usec);
> +               buf += digs;
> +               break;
>             case 'd':
>                 if (tm->tm_mday > 9 || !strip)
>                     *buf++ = '0' + tm->tm_mday / 10;
> diff --git a/Src/watch.c b/Src/watch.c
> index 5231579..8dea0b4 100644
> --- a/Src/watch.c
> +++ b/Src/watch.c
> @@ -330,7 +330,7 @@ watchlog2(int inout, WATCH_STRUCT_UTMP *u, char *fmt,
> int prnt, int fini)
>                     }
>                     timet = getlogtime(u, inout);
>                     tm = localtime(&timet);
> -                   ztrftime(buf, 40, fm2, tm);
> +                   ztrftime(buf, 40, fm2, tm, 0L);
>                     printf("%s", (*buf == ' ') ? buf + 1 : buf);
>                     break;
>                 case '%':
>