release/src/router/busybox/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 #if ENABLE_EXPAND
  33 static void expand(FILE *file, int tab_size, unsigned opt)
  34 {
  35         char *line;
  36
  37         tab_size = -tab_size;
  38
  39         while ((line = xmalloc_fgets(file)) != NULL) {
  40                 int pos;
  41                 unsigned char c;
  42                 char *ptr = line;
  43
  44                 goto start;
  45                 while ((c = *ptr) != '\0') {
  46                         if ((opt & OPT_INITIAL) && !isblank(c)) {
  47                                 fputs(ptr, stdout);
  48                                 break;
  49                         }
  50                         ptr++;
  51                         if (c == '\t') {
  52                                 c = ' ';
  53                                 while (++pos < 0)
  54                                         bb_putchar(c);
  55                         }
  56                         bb_putchar(c);
  57                         if (++pos >= 0) {
  58  start:
  59                                 pos = tab_size;
  60                         }
  61                 }
  62                 free(line);
  63         }
  64 }
  65 #endif
  66
  67 #if ENABLE_UNEXPAND
  68 static void unexpand(FILE *file, unsigned tab_size, unsigned opt)
  69 {
  70         char *line;
  71
  72         while ((line = xmalloc_fgets(file)) != NULL) {
  73                 char *ptr = line;
  74                 unsigned column = 0;
  75
  76                 while (*ptr) {
  77                         unsigned n;
  78
  79                         while (*ptr == ' ') {
  80                                 column++;
  81                                 ptr++;
  82                         }
  83                         if (*ptr == '\t') {
  84                                 column += tab_size - (column % tab_size);
  85                                 ptr++;
  86                                 continue;
  87                         }
  88
  89                         n = column / tab_size;
  90                         column = column % tab_size;
  91                         while (n--)
  92                                 putchar('\t');
  93
  94                         if ((opt & OPT_INITIAL) && ptr != line) {
  95                                 printf("%*s%s", column, "", ptr);
  96                                 break;
  97                         }
  98                         n = strcspn(ptr, "\t ");
  99                         printf("%*s%.*s", column, "", n, ptr);
 100                         ptr += n;
 101                         column = (column + n) % tab_size;
 102                 }
 103                 free(line);
 104         }
 105 }
 106 #endif
 107
 108 int expand_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 109 int expand_main(int argc UNUSED_PARAM, char **argv)
 110 {
 111         /* Default 8 spaces for 1 tab */
 112         const char *opt_t = "8";
 113         FILE *file;
 114         unsigned tab_size;
 115         unsigned opt;
 116         int exit_status = EXIT_SUCCESS;
 117
 118 #if ENABLE_FEATURE_EXPAND_LONG_OPTIONS
 119         static const char expand_longopts[] ALIGN1 =
 120                 /* name, has_arg, val */
 121                 "initial\0"          No_argument       "i"
 122                 "tabs\0"             Required_argument "t"
 123         ;
 124 #endif
 125 #if ENABLE_FEATURE_UNEXPAND_LONG_OPTIONS
 126         static const char unexpand_longopts[] ALIGN1 =
 127                 /* name, has_arg, val */
 128                 "first-only\0"       No_argument       "i"
 129                 "tabs\0"             Required_argument "t"
 130                 "all\0"              No_argument       "a"
 131         ;
 132 #endif
 133
 134         if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e')) {
 135                 USE_FEATURE_EXPAND_LONG_OPTIONS(applet_long_options = expand_longopts);
 136                 opt = getopt32(argv, "it:", &opt_t);
 137         } else {
 138                 USE_FEATURE_UNEXPAND_LONG_OPTIONS(applet_long_options = unexpand_longopts);
 139                 /* -t NUM sets also -a */
 140                 opt_complementary = "ta";
 141                 opt = getopt32(argv, "ft:a", &opt_t);
 142                 /* -f --first-only is the default */
 143                 if (!(opt & OPT_ALL)) opt |= OPT_INITIAL;
 144         }
 145         tab_size = xatou_range(opt_t, 1, UINT_MAX);
 146
 147         argv += optind;
 148
 149         if (!*argv) {
 150                 *--argv = (char*)bb_msg_standard_input;
 151         }
 152         do {
 153                 file = fopen_or_warn_stdin(*argv);
 154                 if (!file) {
 155                         exit_status = EXIT_FAILURE;
 156                         continue;
 157                 }
 158
 159                 if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e'))
 160                         USE_EXPAND(expand(file, tab_size, opt));
 161                 else
 162                         USE_UNEXPAND(unexpand(file, tab_size, opt));
 163
 164                 /* Check and close the file */
 165                 if (fclose_if_not_stdin(file)) {
 166                         bb_simple_perror_msg(*argv);
 167                         exit_status = EXIT_FAILURE;
 168                 }
 169                 /* If stdin also clear EOF */
 170                 if (file == stdin)
 171                         clearerr(file);
 172         } while (*++argv);
 173
 174         /* Now close stdin also */
 175         /* (if we didn't read from it, it's a no-op) */
 176         if (fclose(stdin))
 177                 bb_perror_msg_and_die(bb_msg_standard_input);
 178
 179         fflush_stdout_and_exit(exit_status);
 180 }