xref: /src/bin/echo/echo.c

/* $NetBSD: echo.c,v 1.11 2003/08/07 09:05:12 agc Exp $	*/

/*
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT(
"@(#) Copyright (c) 1989, 1993\n\
	The Regents of the University of California.  All rights reserved.\n");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)echo.c	8.1 (Berkeley) 5/31/93";
#else
__RCSID("$NetBSD: echo.c,v 1.11 2003/08/07 09:05:12 agc Exp $");
#endif
#endif /* not lint */

#include <sys/param.h>

#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <vis.h>

int stdout_ok;

int main(int, char *[]);
char *printescaped(const char *);

/* ARGSUSED */
int
main(int argc, char *argv[])
{
	int nflag;

	stdout_ok = isatty(STDOUT_FILENO);
	/* This utility may NOT do getopt(3) option parsing. */
	if (*++argv && !strcmp(*argv, "-n")) {
		++argv;
		nflag = 1;
	}
	else
		nflag = 0;

	while (*argv) {
		char *n;
		n = printescaped(*argv);
		(void)printf("%s", n);
		free(n);
		if (*++argv)
			(void)putchar(' ');
	}
	if (nflag == 0)
		(void)putchar('\n');
	exit(0);
	/* NOTREACHED */
}

char *
printescaped(const char *src)
{
	size_t len;
	char *retval;

	len = strlen(src);
	if (len != 0 && SIZE_T_MAX/len <= 4) {
		errx(EXIT_FAILURE, "%s: name too long", src);
		/* NOTREACHED */
	}

	retval = (char *)malloc(4*len+1);
	if (retval != NULL) {
		if (stdout_ok)
			(void)strvis(retval, src, VIS_NL | VIS_CSTYLE);
		else
			(void)strcpy(retval, src);
		return retval;
	} else
		errx(EXIT_FAILURE, "out of memory!");
		/* NOTREACHED */
}