freebsd-dev/bin/echo/echo.c
Alfred Perlstein 6188858ae1 clarify code:
add comments.
don't get the length of each arg passed, only the last one.
check against == or != NULL rather than using a pointer value as
truth test.
2002-03-04 05:30:04 +00:00

94 lines
3.0 KiB
C

/*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*/
#ifndef lint
static char const 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";
#endif
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* ARGSUSED */
int
main(int argc __unused, char *argv[])
{
int nflag; /* if not set, output a trailing newline. */
/* This utility may NOT do getopt(3) option parsing. */
if (*++argv && !strcmp(*argv, "-n")) {
++argv;
nflag = 1;
}
else
nflag = 0;
while (argv[0] != NULL) {
/*
* If the next argument is NULL then this is this
* the last argument, therefore we need to check
* for a trailing \c.
*/
if (argv[1] == NULL) {
size_t len;
len = strlen(argv[0]);
/* is there room for a '\c' and is there one? */
if (len >= 2 &&
argv[0][len - 2] == '\\' &&
argv[0][len - 1] == 'c') {
/* chop it and set the no-newline flag. */
argv[0][len - 2] = '\0';
nflag = 1;
}
}
(void)printf("%s", argv[0]);
if (*++argv)
putchar(' ');
}
if (!nflag)
putchar('\n');
return 0;
}