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 source tree.
   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 //usage:#define expand_trivial_usage
  25 //usage:       "[-i] [-t N] [FILE]..."
  26 //usage:#define expand_full_usage "\n\n"
  27 //usage:       "Convert tabs to spaces, writing to stdout\n"
  28 //usage:     "\nOptions:"
  29 //usage:        IF_FEATURE_EXPAND_LONG_OPTIONS(
  30 //usage:     "\n        -i,--initial    Don't convert tabs after non blanks"
  31 //usage:     "\n        -t,--tabs=N     Tabstops every N chars"
  32 //usage:        )
  33 //usage:        IF_NOT_FEATURE_EXPAND_LONG_OPTIONS(
  34 //usage:     "\n        -i      Don't convert tabs after non blanks"
  35 //usage:     "\n        -t      Tabstops every N chars"
  36 //usage:        )
  37
  38 //usage:#define unexpand_trivial_usage
  39 //usage:       "[-fa][-t N] [FILE]..."
  40 //usage:#define unexpand_full_usage "\n\n"
  41 //usage:       "Convert spaces to tabs, writing to stdout\n"
  42 //usage:     "\nOptions:"
  43 //usage:        IF_FEATURE_UNEXPAND_LONG_OPTIONS(
  44 //usage:     "\n        -a,--all        Convert all blanks"
  45 //usage:     "\n        -f,--first-only Convert only leading blanks"
  46 //usage:     "\n        -t,--tabs=N     Tabstops every N chars"
  47 //usage:        )
  48 //usage:        IF_NOT_FEATURE_UNEXPAND_LONG_OPTIONS(
  49 //usage:     "\n        -a      Convert all blanks"
  50 //usage:     "\n        -f      Convert only leading blanks"
  51 //usage:     "\n        -t N    Tabstops every N chars"
  52 //usage:        )
  53
  54 #include "libbb.h"
  55 #include "unicode.h"
  56
  57 enum {
  58         OPT_INITIAL     = 1 << 0,
  59         OPT_TABS        = 1 << 1,
  60         OPT_ALL         = 1 << 2,
  61 };
  62
  63 #if ENABLE_EXPAND
  64 static void expand(FILE *file, unsigned tab_size, unsigned opt)
  65 {
  66         char *line;
  67
  68         while ((line = xmalloc_fgets(file)) != NULL) {
  69                 unsigned char c;
  70                 char *ptr;
  71                 char *ptr_strbeg;
  72
  73                 ptr = ptr_strbeg = line;
  74                 while ((c = *ptr) != '\0') {
  75                         if ((opt & OPT_INITIAL) && !isblank(c)) {
  76                                 /* not space or tab */
  77                                 break;
  78                         }
  79                         if (c == '\t') {
  80                                 unsigned len;
  81                                 *ptr = '\0';
  82 # if ENABLE_UNICODE_SUPPORT
  83                                 {
  84                                         uni_stat_t uni_stat;
  85                                         printable_string(&uni_stat, ptr_strbeg);
  86                                         len = uni_stat.unicode_width;
  87                                 }
  88 # else
  89                                 len = ptr - ptr_strbeg;
  90 # endif
  91                                 len = tab_size - (len % tab_size);
  92                                 /*while (ptr[1] == '\t') { ptr++; len += tab_size; } - can handle many tabs at once */
  93                                 printf("%s%*s", ptr_strbeg, len, "");
  94                                 ptr_strbeg = ptr + 1;
  95                         }
  96                         ptr++;
  97                 }
  98                 fputs(ptr_strbeg, stdout);
  99                 free(line);
 100         }
 101 }
 102 #endif
 103
 104 #if ENABLE_UNEXPAND
 105 static void unexpand(FILE *file, unsigned tab_size, unsigned opt)
 106 {
 107         char *line;
 108
 109         while ((line = xmalloc_fgets(file)) != NULL) {
 110                 char *ptr = line;
 111                 unsigned column = 0;
 112
 113                 while (*ptr) {
 114                         unsigned n;
 115                         unsigned len = 0;
 116
 117                         while (*ptr == ' ') {
 118                                 ptr++;
 119                                 len++;
 120                         }
 121                         column += len;
 122                         if (*ptr == '\t') {
 123                                 column += tab_size - (column % tab_size);
 124                                 ptr++;
 125                                 continue;
 126                         }
 127
 128                         n = column / tab_size;
 129                         if (n) {
 130                                 len = column = column % tab_size;
 131                                 while (n--)
 132                                         putchar('\t');
 133                         }
 134
 135                         if ((opt & OPT_INITIAL) && ptr != line) {
 136                                 printf("%*s%s", len, "", ptr);
 137                                 break;
 138                         }
 139                         n = strcspn(ptr, "\t ");
 140                         printf("%*s%.*s", len, "", n, ptr);
 141 # if ENABLE_UNICODE_SUPPORT
 142                         {
 143                                 char c;
 144                                 uni_stat_t uni_stat;
 145                                 c = ptr[n];
 146                                 ptr[n] = '\0';
 147                                 printable_string(&uni_stat, ptr);
 148                                 len = uni_stat.unicode_width;
 149                                 ptr[n] = c;
 150                         }
 151 # else
 152                         len = n;
 153 # endif
 154                         ptr += n;
 155                         column = (column + len) % tab_size;
 156                 }
 157                 free(line);
 158         }
 159 }
 160 #endif
 161
 162 int expand_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 163 int expand_main(int argc UNUSED_PARAM, char **argv)
 164 {
 165         /* Default 8 spaces for 1 tab */
 166         const char *opt_t = "8";
 167         FILE *file;
 168         unsigned tab_size;
 169         unsigned opt;
 170         int exit_status = EXIT_SUCCESS;
 171
 172 #if ENABLE_FEATURE_EXPAND_LONG_OPTIONS
 173         static const char expand_longopts[] ALIGN1 =
 174                 /* name, has_arg, val */
 175                 "initial\0"          No_argument       "i"
 176                 "tabs\0"             Required_argument "t"
 177         ;
 178 #endif
 179 #if ENABLE_FEATURE_UNEXPAND_LONG_OPTIONS
 180         static const char unexpand_longopts[] ALIGN1 =
 181                 /* name, has_arg, val */
 182                 "first-only\0"       No_argument       "i"
 183                 "tabs\0"             Required_argument "t"
 184                 "all\0"              No_argument       "a"
 185         ;
 186 #endif
 187         init_unicode();
 188
 189         if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e')) {
 190                 IF_FEATURE_EXPAND_LONG_OPTIONS(applet_long_options = expand_longopts);
 191                 opt = getopt32(argv, "it:", &opt_t);
 192         } else {
 193                 IF_FEATURE_UNEXPAND_LONG_OPTIONS(applet_long_options = unexpand_longopts);
 194                 /* -t NUM sets also -a */
 195                 opt_complementary = "ta";
 196                 opt = getopt32(argv, "ft:a", &opt_t);
 197                 /* -f --first-only is the default */
 198                 if (!(opt & OPT_ALL)) opt |= OPT_INITIAL;
 199         }
 200         tab_size = xatou_range(opt_t, 1, UINT_MAX);
 201
 202         argv += optind;
 203
 204         if (!*argv) {
 205                 *--argv = (char*)bb_msg_standard_input;
 206         }
 207         do {
 208                 file = fopen_or_warn_stdin(*argv);
 209                 if (!file) {
 210                         exit_status = EXIT_FAILURE;
 211                         continue;
 212                 }
 213
 214                 if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e'))
 215                         IF_EXPAND(expand(file, tab_size, opt));
 216                 else
 217                         IF_UNEXPAND(unexpand(file, tab_size, opt));
 218
 219                 /* Check and close the file */
 220                 if (fclose_if_not_stdin(file)) {
 221                         bb_simple_perror_msg(*argv);
 222                         exit_status = EXIT_FAILURE;
 223                 }
 224                 /* If stdin also clear EOF */
 225                 if (file == stdin)
 226                         clearerr(file);
 227         } while (*++argv);
 228
 229         /* Now close stdin also */
 230         /* (if we didn't read from it, it's a no-op) */
 231         if (fclose(stdin))
 232                 bb_perror_msg_and_die(bb_msg_standard_input);
 233
 234         fflush_stdout_and_exit(exit_status);
 235 }