git.maemo.org Git - busybox4maemo/blob - coreutils/expand.c

   1 /* expand - convert tabs to spaces
   2  * unexpand - convert spaces to tabs
   3  *
   4  * Copyright (C) 89, 91, 1995-2006 Free Software Foundation, Inc.
   5  *
   6  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
   7  *
   8  * David MacKenzie <djm@gnu.ai.mit.edu>
   9  *
  10  * Options for expand:
  11  * -t num  --tabs=NUM      Convert tabs to num spaces (default 8 spaces).
  12  * -i      --initial       Only convert initial tabs on each line to spaces.
  13  *
  14  * Options for unexpand:
  15  * -a      --all           Convert all blanks, instead of just initial blanks.
  16  * -f      --first-only    Convert only leading sequences of blanks (default).
  17  * -t num  --tabs=NUM      Have tabs num characters apart instead of 8.
  18  *
  19  *  Busybox version (C) 2007 by Tito Ragusa <farmatito@tiscali.it>
  20  *
  21  *  Caveat: this versions of expand and unexpand don't accept tab lists.
  22  */
  23
  24 #include "libbb.h"
  25
  26 enum {
  27         OPT_INITIAL     = 1 << 0,
  28         OPT_TABS        = 1 << 1,
  29         OPT_ALL         = 1 << 2,
  30 };
  31
  32 static void xputchar(char c)
  33 {
  34         if (putchar(c) < 0)
  35                 bb_error_msg_and_die(bb_msg_write_error);
  36 }
  37
  38 #if ENABLE_EXPAND
  39 static void expand(FILE *file, unsigned tab_size, unsigned opt)
  40 {
  41         char *line;
  42         char *ptr;
  43         int convert;
  44         int pos;
  45
  46         /* Increment tab_size by 1 locally.*/
  47         tab_size++;
  48
  49         while ((line = xmalloc_fgets(file)) != NULL) {
  50                 convert = 1;
  51                 pos = 0;
  52                 ptr = line;
  53                 while (*line) {
  54                         pos++;
  55                         if (*line == '\t' && convert) {
  56                                 for (; pos < tab_size; pos++) {
  57                                         xputchar(' ');
  58                                 }
  59                         } else {
  60                                 if ((opt & OPT_INITIAL) && !isblank(*line)) {
  61                                         convert = 0;
  62                                 }
  63                                 xputchar(*line);
  64                         }
  65                         if (pos == tab_size) {
  66                                 pos = 0;
  67                         }
  68                         line++;
  69                 }
  70                 free(ptr);
  71         }
  72 }
  73 #endif
  74
  75 #if ENABLE_UNEXPAND
  76 static void unexpand(FILE *file, unsigned int tab_size, unsigned opt)
  77 {
  78         char *line;
  79         char *ptr;
  80         int convert;
  81         int pos;
  82         int i = 0;
  83         int column = 0;
  84
  85         while ((line = xmalloc_fgets(file)) != NULL) {
  86                 convert = 1;
  87                 pos = 0;
  88                 ptr = line;
  89                 while (*line) {
  90                         while ((*line == ' ' || *line == '\t') && convert) {
  91                                 pos += (*line == ' ') ? 1 : tab_size;
  92                                 line++;
  93                                 column++;
  94                                 if ((opt & OPT_ALL) && column == tab_size) {
  95                                         column = 0;
  96                                         goto put_tab;
  97                                 }
  98                         }
  99                         if (pos) {
 100                                 i = pos / tab_size;
 101                                 if (i) {
 102                                         for (; i > 0; i--) {
 103  put_tab:
 104                                                 xputchar('\t');
 105                                         }
 106                                 } else {
 107                                         for (i = pos % tab_size; i > 0; i--) {
 108                                                 xputchar(' ');
 109                                         }
 110                                 }
 111                                 pos = 0;
 112                         } else {
 113                                 if (opt & OPT_INITIAL) {
 114                                         convert = 0;
 115                                 }
 116                                 if (opt & OPT_ALL) {
 117                                         column++;
 118                                 }
 119                                 xputchar(*line);
 120                                 line++;
 121                         }
 122                 }
 123                 free(ptr);
 124         }
 125 }
 126 #endif
 127
 128 int expand_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 129 int expand_main(int argc ATTRIBUTE_UNUSED, char **argv)
 130 {
 131         /* Default 8 spaces for 1 tab */
 132         const char *opt_t = "8";
 133         FILE *file;
 134         unsigned tab_size;
 135         unsigned opt;
 136         int exit_status = EXIT_SUCCESS;
 137
 138 #if ENABLE_FEATURE_EXPAND_LONG_OPTIONS
 139         static const char expand_longopts[] ALIGN1 =
 140                 /* name, has_arg, val */
 141                 "initial\0"          No_argument       "i"
 142                 "tabs\0"             Required_argument "t"
 143         ;
 144 #endif
 145 #if ENABLE_FEATURE_UNEXPAND_LONG_OPTIONS
 146         static const char unexpand_longopts[] ALIGN1 =
 147                 /* name, has_arg, val */
 148                 "first-only\0"       No_argument       "i"
 149                 "tabs\0"             Required_argument "t"
 150                 "all\0"              No_argument       "a"
 151         ;
 152 #endif
 153
 154         if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e')) {
 155                 USE_FEATURE_EXPAND_LONG_OPTIONS(applet_long_options = expand_longopts);
 156                 opt = getopt32(argv, "it:", &opt_t);
 157         } else {
 158                 USE_FEATURE_UNEXPAND_LONG_OPTIONS(applet_long_options = unexpand_longopts);
 159                 /* -t NUM sets also -a */
 160                 opt_complementary = "ta";
 161                 opt = getopt32(argv, "ft:a", &opt_t);
 162                 /* -f --first-only is the default */
 163                 if (!(opt & OPT_ALL)) opt |= OPT_INITIAL;
 164         }
 165         tab_size = xatou_range(opt_t, 1, UINT_MAX);
 166
 167         argv += optind;
 168
 169         if (!*argv) {
 170                 *--argv = (char*)bb_msg_standard_input;
 171         }
 172         do {
 173                 file = fopen_or_warn_stdin(*argv);
 174                 if (!file) {
 175                         exit_status = EXIT_FAILURE;
 176                         continue;
 177                 }
 178
 179                 if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e'))
 180                         USE_EXPAND(expand(file, tab_size, opt));
 181                 else
 182                         USE_UNEXPAND(unexpand(file, tab_size, opt));
 183
 184                 /* Check and close the file */
 185                 if (fclose_if_not_stdin(file)) {
 186                         bb_simple_perror_msg(*argv);
 187                         exit_status = EXIT_FAILURE;
 188                 }
 189                 /* If stdin also clear EOF */
 190                 if (file == stdin)
 191                         clearerr(file);
 192         } while (*++argv);
 193
 194         /* Now close stdin also */
 195         /* (if we didn't read from it, it's a no-op) */
 196         if (fclose(stdin))
 197                 bb_perror_msg_and_die(bb_msg_standard_input);
 198
 199         fflush_stdout_and_exit(exit_status);
 200 }