text-utils/rev.c

   1 /*-
   2  * Copyright (c) 1987, 1992 The Regents of the University of California.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * Modified for Linux by Charles Hannum (mycroft@gnu.ai.mit.edu)
  34  *                   and Brian Koehmstedt (bpk@gnu.ai.mit.edu)
  35  *
  36  * Wed Sep 14 22:26:00 1994: Patch from bjdouma <bjdouma@xs4all.nl> to handle
  37  *                           last line that has no newline correctly.
  38  * 3-Jun-1998: Patched by Nicolai Langfeldt to work better on Linux:
  39  *      Handle any-length-lines.  Code copied from util-linux' setpwnam.c
  40  * 1999-02-22 Arkadiusz Miśkiewicz <misiek@pld.ORG.PL>
  41  *      added Native Language Support
  42  * 1999-09-19 Bruno Haible <haible@clisp.cons.org>
  43  *      modified to work correctly in multi-byte locales
  44  * July 2010 - Davidlohr Bueso <dave@gnu.org>
  45  *      Fixed memory leaks (including Linux signal handling)
  46  *      Added some memory allocation error handling
  47  *      Lowered the default buffer size to 256, instead of 512 bytes
  48  *      Changed tab indentation to 8 chars for better reading the code
  49  */
  50
  51 #include <stdarg.h>
  52 #include <sys/types.h>
  53 #include <errno.h>
  54 #include <stdio.h>
  55 #include <stdlib.h>
  56 #include <string.h>
  57 #include <unistd.h>
  58 #include <signal.h>
  59 #include <getopt.h>
  60
  61 #include "nls.h"
  62 #include "xalloc.h"
  63 #include "widechar.h"
  64 #include "c.h"
  65 #include "closestream.h"
  66
  67 static void sig_handler(int signo __attribute__ ((__unused__)))
  68 {
  69         _exit(EXIT_SUCCESS);
  70 }
  71
  72 static void __attribute__((__noreturn__)) usage(void)
  73 {
  74         FILE *out = stdout;
  75         fprintf(out, _("Usage: %s [options] [file ...]\n"),
  76                 program_invocation_short_name);
  77
  78         fputs(USAGE_SEPARATOR, out);
  79         fputs(_("Reverse lines characterwise.\n"), out);
  80
  81         fputs(USAGE_OPTIONS, out);
  82         printf(USAGE_HELP_OPTIONS(16));
  83         printf(USAGE_MAN_TAIL("rev(1)"));
  84
  85         exit(EXIT_SUCCESS);
  86 }
  87
  88 static void reverse_str(wchar_t *str, size_t n)
  89 {
  90         size_t i;
  91
  92         for (i = 0; i < n / 2; ++i) {
  93                 wchar_t tmp = str[i];
  94                 str[i] = str[n - 1 - i];
  95                 str[n - 1 - i] = tmp;
  96         }
  97 }
  98
  99 static size_t read_line(wchar_t sep, wchar_t *str, size_t n, FILE *stream)
 100 {
 101         size_t r = 0;
 102         while (r < n) {
 103                 wint_t c = fgetwc(stream);
 104                 if (c == WEOF)
 105                         break;
 106                 str[r++] = c;
 107                 if ((wchar_t) c == sep)
 108                         break;
 109         }
 110         return r;
 111 }
 112
 113 static void write_line(wchar_t *str, size_t n, FILE *stream)
 114 {
 115         for (size_t i = 0; i < n; i++)
 116                 fputwc(str[i], stream);
 117 }
 118
 119 int main(int argc, char *argv[])
 120 {
 121         char const *filename = "stdin";
 122         wchar_t *buf;
 123         wchar_t sep = L'\n';
 124         size_t len, bufsiz = BUFSIZ;
 125         FILE *fp = stdin;
 126         int ch, rval = EXIT_SUCCESS;
 127         uintmax_t line;
 128
 129         static const struct option longopts[] = {
 130                 { "zero",       no_argument,       NULL, '0' },
 131                 { "version",    no_argument,       NULL, 'V' },
 132                 { "help",       no_argument,       NULL, 'h' },
 133                 { NULL,         0, NULL, 0 }
 134         };
 135
 136         setlocale(LC_ALL, "");
 137         bindtextdomain(PACKAGE, LOCALEDIR);
 138         textdomain(PACKAGE);
 139         close_stdout_atexit();
 140
 141         signal(SIGINT, sig_handler);
 142         signal(SIGTERM, sig_handler);
 143
 144         while ((ch = getopt_long(argc, argv, "Vh0", longopts, NULL)) != -1)
 145                 switch(ch) {
 146                 case '0':
 147                         sep = L'\0';
 148                         break;
 149                 case 'V':
 150                         print_version(EXIT_SUCCESS);
 151                 case 'h':
 152                         usage();
 153                 default:
 154                         errtryhelp(EXIT_FAILURE);
 155                 }
 156
 157         argc -= optind;
 158         argv += optind;
 159
 160         buf = xreallocarray(NULL, bufsiz, sizeof(wchar_t));
 161
 162         do {
 163                 if (*argv) {
 164                         if ((fp = fopen(*argv, "r")) == NULL) {
 165                                 warn(_("cannot open %s"), *argv );
 166                                 rval = EXIT_FAILURE;
 167                                 ++argv;
 168                                 continue;
 169                         }
 170                         filename = *argv++;
 171                 }
 172
 173                 line = 0;
 174                 while (!feof(fp)) {
 175                         len = read_line(sep, buf, bufsiz, fp);
 176                         if (len == 0)
 177                                 continue;
 178
 179                         /* This is my hack from setpwnam.c -janl */
 180                         while (len == bufsiz && !feof(fp)) {
 181                                 /* Extend input buffer if it failed getting the whole line */
 182                                 /* So now we double the buffer size */
 183                                 bufsiz *= 2;
 184
 185                                 buf = xreallocarray(buf, bufsiz, sizeof(wchar_t));
 186
 187                                 /* And fill the rest of the buffer */
 188                                 len += read_line(sep, &buf[len], bufsiz/2, fp);
 189                         }
 190                         reverse_str(buf, buf[len - 1] == sep ? len - 1 : len);
 191                         write_line(buf, len, stdout);
 192                         line++;
 193                 }
 194                 if (ferror(fp)) {
 195                         warn("%s: %ju", filename, line);
 196                         rval = EXIT_FAILURE;
 197                 }
 198                 if (fp != stdin)
 199                         fclose(fp);
 200         } while(*argv);
 201
 202         free(buf);
 203         return rval;
 204 }
 205