utils/src/time.c

109 lines
2.0 KiB
C

/* time.c */
#include <sys/times.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
/* time */
static int _time_error(char * error, int ret);
static int _time_exec(char * argv[]);
static int _time_print(long real, long user, long sys);
static int _time(char * argv[])
{
pid_t pid;
int status;
struct tms tmsbuf;
clock_t cbefore, cafter;
if((cbefore = times(NULL)) == (clock_t)-1)
return _time_error("times", 2);
if((pid = fork()) == -1)
return _time_error("fork", 2);
if(pid == 0)
return _time_exec(argv);
for(;;)
{
if(waitpid(pid, &status, 0) == -1)
return _time_error("waitpid", 2);
if(WIFEXITED(status))
break;
}
if((cafter = times(&tmsbuf)) == (clock_t)-1)
return _time_error("times", 2);
return _time_print(cafter - cbefore,
tmsbuf.tms_utime + tmsbuf.tms_cutime,
tmsbuf.tms_stime + tmsbuf.tms_cstime);
}
static int _time_error(char * message, int ret)
{
fprintf(stderr, "%s", "time: ");
perror(message);
return ret;
}
static int _time_exec(char * argv[])
{
execvp(argv[0], argv);
if(errno == ENOENT)
return _time_error(argv[0], 127);
return _time_error(argv[0], 126);
}
static int _time_print(long real, long user, long sys)
{
char * args[3] = { "real", "user", "sys" };
long * argl[3] = { &real, &user, &sys };
int i;
long l;
long r;
if((r = sysconf(_SC_CLK_TCK)) == -1)
{
_time_error("sysconf", 0);
r = 100;
}
for(i = 0; i < 3; i++)
{
l = *argl[i] / r;
if(l * r > *argl[i])
l--;
/* FIXME */
fprintf(stderr, "%s %ld.%02lds\n", args[i], l, *argl[i] % r);
}
return 0;
}
/* usage */
static int _usage(void)
{
fprintf(stderr, "%s", "Usage: time [-p] utility [argument...]\n\
-p force the POSIX locale\n");
return 1;
}
/* main */
int main(int argc, char * argv[])
{
int o;
while((o = getopt(argc, argv, "p")) != -1)
{
if(o == 'p')
continue;
if(o == '?')
return _usage();
}
if(optind == argc)
return _usage();
return _time(&argv[optind]);
}