bring rev back into the main-line source tree

[unix-history] / usr / src / usr.bin / rev / rev.c

/*-
* Copyright (c) 1987, 1992 The Regents of the University of California.
* All rights reserved.
*
* %sccs.include.redist.c%
*/

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

#ifndef lint
static char sccsid[] = "@(#)rev.c       5.1 (Berkeley) %G%";
#endif /* not lint */

#include <sys/types.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

void usage __P((void));
void warn __P((const char *, ...));

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: %s", *argv, strerror(errno));
                               rval = 1;
                               ++argv;
                               continue;
                       }
                       filename = *argv++;
               }
               while (p = fgetline(fp, &len)) {
                       t = p + len - 1;
                       for (t = p + len - 1; t >= p; --t)
                               putchar(*t);
                       putchar('\n');
               }
               if (ferror(fp)) {
                       warn("%s: %s", filename, strerror(errno));
                       rval = 1;
               }
               (void)fclose(fp);
       } while(*argv);
       exit(0);
}

#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif

void
#if __STDC__
warn(const char *fmt, ...)
#else
warn(fmt, va_alist)
       char *fmt;
       va_dcl
#endif
{
       va_list ap;
#if __STDC__
       va_start(ap, fmt);
#else
       va_start(ap);
#endif
       (void)fprintf(stderr, "rev: ");
       (void)vfprintf(stderr, fmt, ap);
       va_end(ap);
       (void)fprintf(stderr, "\n");
}

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