times1.c

UNIX编程高级环境（第二版）的进程部分的程序源码

#include    <sys/times.h>
#include    "ourhdr.h"

static void    pr_times(clock_t, struct tms *, struct tms *);
static void    do_cmd(char *);

int
main(int argc, char *argv[])
{
    int        i;

    for (i = 1; i < argc; i++)
        do_cmd(argv[i]);    /* once for each command-line arg */
    exit(0);
}
static void
do_cmd(char *cmd)        /* execute and time the "cmd" */
{
    struct tms    tmsstart, tmsend;
    clock_t        start, end;
    int            status;

    fprintf(stderr, "\ncommand: %s\n", cmd);

    if ( (start = times(&tmsstart)) == -1)    /* starting values */
        err_sys("times error");

    if ( (status = system(cmd)) < 0)        /* execute command */
        err_sys("system() error");

    if ( (end = times(&tmsend)) == -1)        /* ending values */
        err_sys("times error");

    pr_times(end-start, &tmsstart, &tmsend);
    pr_exit(status);
}
static void
pr_times(clock_t real, struct tms *tmsstart, struct tms *tmsend)
{
    static long        clktck = 0;

    if (clktck == 0)    /* fetch clock ticks per second first time */
        if ( (clktck = sysconf(_SC_CLK_TCK)) < 0)
            err_sys("sysconf error");
    fprintf(stderr, "  real:  %7.2f\n", real / (double) clktck);
    fprintf(stderr, "  user:  %7.2f\n",
            (tmsend->tms_utime - tmsstart->tms_utime) / (double) clktck);
    fprintf(stderr, "  sys:   %7.2f\n",
            (tmsend->tms_stime - tmsstart->tms_stime) / (double) clktck);
    fprintf(stderr, "  child user:  %7.2f\n",
            (tmsend->tms_cutime - tmsstart->tms_cutime) / (double) clktck);
    fprintf(stderr, "  child sys:   %7.2f\n",
            (tmsend->tms_cstime - tmsstart->tms_cstime) / (double) clktck);
}