utils

time.c (2117B)

// Collection of Unix tools, comparable to coreutils
// SPDX-FileCopyrightText: 2017-2022 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
// SPDX-License-Identifier: MPL-2.0
#define _POSIX_C_SOURCE 200809L
#include <errno.h>     // errno
#include <stdio.h>     // perror, fprintf
#include <stdlib.h>    // abort
#include <sys/times.h> // times
#include <sys/wait.h>  // waitpid
#include <unistd.h>    // sysconf, fork, execvp, getopt
void
usage()
{
	fprintf(stderr, "Usage: time command [argument ...]\n");
}
int
main(int argc, char *argv[])
{
	struct tms tms;
	int ret = 0;
	if(argc <= 1)
	{
		usage();
		return 0;
	}
	int c = -1;
	while((c = getopt(argc, argv, ":p")) != -1)
	{
		switch(c)
		{
		case 'p': // POSIX format (default)
			break;
		case ':':
			fprintf(stderr, "time: Error: Missing operand for option: '-%c'\n", optopt);
			usage();
			return 1;
		case '?':
			fprintf(stderr, "time: Error: Unrecognised option: '-%c'\n", optopt);
			usage();
			return 1;
		}
	}
	argc -= optind;
	argv += optind;
	(void)argc;
	long ticks = sysconf(_SC_CLK_TCK);
	if(ticks <= 0)
	{
		perror("time: sysconf(_SC_CLK_TCK)");
		return 1;
	}
	clock_t t0 = times(&tms);
	if(t0 == (clock_t)-1)
	{
		perror("time: times");
		return 1;
	}
	// Note: posix_spawnp seems to lack enough error information
	pid_t pid = fork();
	switch(pid)
	{
	case -1:
		perror("time: fork");
		return 1;
	case 0:
		/* flawfinder: ignore. No restrictions on commands is intended */
		execvp(argv[0], argv);
		ret = 126 + (errno == ENOENT);
		perror("time: execvp");
		return ret;
	default:
		break;
	}
	int status = 0;
	waitpid(pid, &status, 0);
	int t1 = times(&tms);
	if(t1 == (clock_t)-1)
	{
		perror("time: times");
		return 1;
	}
	if(WIFSIGNALED(status))
	{
		fprintf(stderr, "time: Command terminated by signal %d\n", WTERMSIG(status));
		ret = 128 + WTERMSIG(status);
	}
	fprintf(stderr,
	        "real %f\nuser %f\nsys %f\n",
	        (t1 - t0) / (double)ticks,
	        tms.tms_cutime / (double)ticks,
	        tms.tms_cstime / (double)ticks);
	if(WIFEXITED(status))
	{
		ret = WEXITSTATUS(status);
	}
	return ret;
}