freebsd-src/usr.bin/rev/rev.c

111 lines
3.0 KiB
C

/*-
* Copyright (c) 1987, 1992, 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 copyright[] =
"@(#) Copyright (c) 1987, 1992, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)rev.c 8.3 (Berkeley) 5/4/95";
#endif /* not lint */
#include <sys/types.h>
#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
void usage __P((void));
int
main(argc, argv)
int argc;
char *argv[];
{
register char *filename, *p, *t;
FILE *fp;
size_t len;
int ch, rval;
while ((ch = getopt(argc, argv, "")) != EOF)
switch(ch) {
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
fp = stdin;
filename = "stdin";
rval = 0;
do {
if (*argv) {
if ((fp = fopen(*argv, "r")) == NULL) {
warn("%s", *argv);
rval = 1;
++argv;
continue;
}
filename = *argv++;
}
while ((p = fgetln(fp, &len)) != NULL) {
if (p[len - 1] == '\n')
--len;
t = p + len - 1;
for (t = p + len - 1; t >= p; --t)
putchar(*t);
putchar('\n');
}
if (ferror(fp)) {
warn("%s", filename);
rval = 1;
}
(void)fclose(fp);
} while(*argv);
exit(rval);
}
void
usage()
{
(void)fprintf(stderr, "usage: rev [file ...]\n");
exit(1);
}