source: trunk/minix/commands/simple/rev.c@ 20

/*-
 * 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 const char copyright[] =
"@(#) Copyright (c) 1987, 1992, 1993\n\
        The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#include <sys/types.h>

#include <errno.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

void usage(void);

int
main(int argc, char *argv[])
{
        const char *filename;
        char p[2000], *t;
        FILE *fp;
        size_t len;
        int ch, rval;

        setlocale(LC_ALL, "");

        while ((ch = getopt(argc, argv, "")) != -1)
                switch(ch) {
                case '?':
                default:
                        usage();
                }

        argc -= optind;
        argv += optind;

        fp = stdin;
        filename = "stdin";
        rval = 0;
        do {
                if (*argv) {
                        if ((fp = fopen(*argv, "r")) == NULL) {
                                perror(*argv);
                                rval = 1;
                                ++argv;
                                continue;
                        }
                        filename = *argv++;
                }
                while ((fgets(p, sizeof(p)-1, fp)) != NULL) {
                        len = strlen(p);
                        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)) {
                        perror(filename);
                        rval = 1;
                }
                (void)fclose(fp);
        } while(*argv);
        exit(rval);
}

void
usage(void)
{
        (void)fprintf(stderr, "usage: rev [file ...]\n");
        exit(1);
}