sbase/time.c
sin d083a94731 time: errno is not guaranteed to be set for sysconf()
0 should be considered an invalid CLK_TCK.
2015-02-28 14:36:50 +00:00

58 lines
1.2 KiB
C

/* See LICENSE file for copyright and license details. */
#include <sys/times.h>
#include <sys/wait.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include "util.h"
static void
usage(void)
{
eprintf("usage: %s [-p] utility [argument ...]\n", argv0);
}
int
main(int argc, char *argv[])
{
pid_t pid;
struct tms tms; /* hold user and sys times */
clock_t rbeg, rend; /* real time */
long ticks; /* per second */
int status;
ARGBEGIN {
case 'p':
break;
default:
usage();
} ARGEND;
if (!*argv)
usage();
if ((ticks = sysconf(_SC_CLK_TCK)) <= 0)
eprintf("sysconf() failed to retrieve clock ticks per second\n");
if ((rbeg = times(&tms)) < 0)
eprintf("times() failed to retrieve start times:");
if (!(pid = fork())) { /* child */
execvp(*argv, argv);
enprintf(errno == ENOENT ? 127 : 126, "failed to exec %s:", *argv);
}
waitpid(pid, &status, 0);
if ((rend = times(&tms)) < 0)
eprintf("times() failed to retrieve end times:");
fprintf(stderr, "real %f\nuser %f\nsys %f\n",
(rend - rbeg) / (double)ticks,
tms.tms_cutime / (double)ticks,
tms.tms_cstime / (double)ticks);
return WIFEXITED(status) ? WEXITSTATUS(status) : 0;
}