utils-std

sleep.c (1640B)

// utils-std: Collection of commonly available Unix tools
// SPDX-FileCopyrightText: 2017 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
// SPDX-License-Identifier: MPL-2.0
#define _POSIX_C_SOURCE 200809L
#include "../libutils/strtodur.h"
#include <errno.h>    // errno
#include <inttypes.h> // PRId64
#include <stdio.h>    // fprintf, perror
#include <string.h>   // strerror
#include <time.h>     // nanosleep
#include <unistd.h>   // execvp
const char *argv0 = "sleep";
int
main(int argc, char *argv[])
{
	struct timespec dur = {.tv_sec = 0, .tv_nsec = 0};
	argc--, argv++;
	if(argc < 1)
	{
		fprintf(stderr, "sleep: error: No duration argument passed\n");
		return 1;
	}
	struct timespec arg_dur = {.tv_sec = 0, .tv_nsec = 0};
	if(strtodur(argv[0], &arg_dur) < 0) return 1;
	dur.tv_sec += arg_dur.tv_sec;
	dur.tv_nsec += arg_dur.tv_nsec;
	if(dur.tv_nsec > 999999999)
	{
		dur.tv_nsec = 0;
		dur.tv_sec += 1;
	}
	if(dur.tv_sec == 0 && dur.tv_nsec == 0)
	{
		fprintf(stderr, "sleep: error: Got a total duration of 0\n");
		return 1;
	}
	argc--, argv++;
	errno = 0;
	if(nanosleep(&dur, &dur) != 0)
	{
		if(errno == EINTR)
		{
			fprintf(stderr,
			        "sleep: warning: Interrupted during sleep, still had %" PRId64 ".%09" PRId64
			        " seconds remaining\n",
			        (int64_t)dur.tv_sec,
			        (int64_t)dur.tv_nsec);
		}
		else
		{
			perror("sleep: error: nanosleep");
			return 1;
		}
	}
	if(argc > 0)
	{
		errno = 0;
		execvp(argv[0], argv);
		fprintf(stderr, "sleep: error: Failed executing command '%s': %s\n", argv[0], strerror(errno));
		return (errno == ENOENT) ? 127 : 126;
	}
	return 0;
}