coreutils

// sleep.c, version 1.0.2

// OMKOV coreutils implementation of POSIX sleep

// Copyright (C) 2020, Jakob Wakeling

// MIT Licence

#include "util/error.h"

#include "util/optget.h"

#include <unistd.h>

#include <stdio.h>

#include <stdint.h>

#define VERSION "1.0.2"

static struct lop lops[] = {

	{ "help",    ARG_NUL, 256 },

	{ "version", ARG_NUL, 257 },

	{ NULL, 0, 0 }

};

static void hlp(void);

static void ver(void);

int main(int ac, char *av[]) { A0 = av[0];

	struct opt opt = OPTGET_INIT; opt.str = ""; opt.lops = lops;

	for (int o; (o = optget(&opt, av, 1)) != -1;) switch (o) {

	case 256: { hlp(); return 0; }

	case 257: { ver(); return 0; }

	default: { return 1; }

	}

	if (opt.ind == ac) { error(1, "missing operand"); }

	register unsigned n = 0, d; register char *p = av[1];

	for (; *p >= '0' && *p <= '9'; ++p) {

		d = (unsigned)*p - '0';

		if (n > (UINTMAX_MAX - d) / 10) { break; }

		n = n * 10 + d;

	}

	if (*p) { error(1, "%s: invalid time interval", av[1]); }

	return (int)sleep(n);

}

static void hlp(void) {

	puts("sleep - suspend execution for an interval\n");

	puts("usage: sleep time\n");

	puts("options:");

	puts("  --help     Display help information");

	puts("  --version  Display version information");

}

static void ver(void) {

	puts("OMKOV coreutils sleep, version " VERSION);

	puts("Copyright (C) 2020, Jakob Wakeling");

	puts("MIT Licence (https://opensource.org/licenses/MIT)");

}