coreutils/tr.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini tr implementation for busybox
   4  *
   5  ** Copyright (c) 1987,1997, Prentice Hall   All rights reserved.
   6  *
   7  * The name of Prentice Hall may not be used to endorse or promote
   8  * products derived from this software without specific prior
   9  * written permission.
  10  *
  11  * Copyright (c) Michiel Huisjes
  12  *
  13  * This version of tr is adapted from Minix tr and was modified
  14  * by Erik Andersen <andersen@codepoet.org> to be used in busybox.
  15  *
  16  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  17  */
  18 /* http://www.opengroup.org/onlinepubs/009695399/utilities/tr.html
  19  * TODO: xdigit, graph, print
  20  */
  21 #include "libbb.h"
  22
  23 #define ASCII 0377
  24
  25 #define TR_OPT_complement       (1<<0)
  26 #define TR_OPT_delete           (1<<1)
  27 #define TR_OPT_squeeze_reps     (1<<2)
  28
  29 static void map(char *pvector,
  30                 unsigned char *string1, unsigned int string1_len,
  31                 unsigned char *string2, unsigned int string2_len)
  32 {
  33         char last = '0';
  34         unsigned int i, j;
  35
  36         for (j = 0, i = 0; i < string1_len; i++) {
  37                 if (string2_len <= j)
  38                         pvector[string1[i]] = last;
  39                 else
  40                         pvector[string1[i]] = last = string2[j++];
  41         }
  42 }
  43
  44 /* supported constructs:
  45  *   Ranges,  e.g.,  0-9   ==>  0123456789
  46  *   Ranges,  e.g.,  [0-9] ==>  0123456789
  47  *   Escapes, e.g.,  \a    ==>  Control-G
  48  *   Character classes, e.g. [:upper:] ==> A...Z
  49  *   Equiv classess, e.g. [=A=] ==> A   (hmmmmmmm?)
  50  */
  51 static unsigned int expand(const char *arg, char *buffer)
  52 {
  53         char *buffer_start = buffer;
  54         unsigned i; /* can't be unsigned char: must be able to hold 256 */
  55         unsigned char ac;
  56
  57         while (*arg) {
  58                 if (*arg == '\\') {
  59                         arg++;
  60                         *buffer++ = bb_process_escape_sequence(&arg);
  61                         continue;
  62                 }
  63                 if (arg[1] == '-') { /* "0-9..." */
  64                         ac = arg[2];
  65                         if (ac == '\0') { /* "0-": copy verbatim */
  66                                 *buffer++ = *arg++; /* copy '0' */
  67                                 continue; /* next iter will copy '-' and stop */
  68                         }
  69                         i = *arg;
  70                         while (i <= ac) /* ok: i is unsigned _int_ */
  71                                 *buffer++ = i++;
  72                         arg += 3; /* skip 0-9 */
  73                         continue;
  74                 }
  75                 if (*arg == '[') { /* "[xyz..." */
  76                         arg++;
  77                         i = *arg++;
  78                         /* "[xyz...", i=x, arg points to y */
  79                         if (ENABLE_FEATURE_TR_CLASSES && i == ':') {
  80 #define CLO ":]\0"
  81                                 static const char classes[] ALIGN1 =
  82                                         "alpha"CLO "alnum"CLO "digit"CLO
  83                                         "lower"CLO "upper"CLO "space"CLO
  84                                         "blank"CLO "punct"CLO "cntrl"CLO;
  85 #define CLASS_invalid 0 /* we increment the retval */
  86 #define CLASS_alpha 1
  87 #define CLASS_alnum 2
  88 #define CLASS_digit 3
  89 #define CLASS_lower 4
  90 #define CLASS_upper 5
  91 #define CLASS_space 6
  92 #define CLASS_blank 7
  93 #define CLASS_punct 8
  94 #define CLASS_cntrl 9
  95 //#define CLASS_xdigit 10
  96 //#define CLASS_graph 11
  97 //#define CLASS_print 12
  98                                 smalluint j;
  99                                 { /* not really pretty.. */
 100                                         char *tmp = xstrndup(arg, 7); // warning: xdigit would need 8, not 7
 101                                         j = index_in_strings(classes, tmp) + 1;
 102                                         free(tmp);
 103                                 }
 104                                 if (j == CLASS_alnum || j == CLASS_digit) {
 105                                         for (i = '0'; i <= '9'; i++)
 106                                                 *buffer++ = i;
 107                                 }
 108                                 if (j == CLASS_alpha || j == CLASS_alnum || j == CLASS_upper) {
 109                                         for (i = 'A'; i <= 'Z'; i++)
 110                                                 *buffer++ = i;
 111                                 }
 112                                 if (j == CLASS_alpha || j == CLASS_alnum || j == CLASS_lower) {
 113                                         for (i = 'a'; i <= 'z'; i++)
 114                                                 *buffer++ = i;
 115                                 }
 116                                 if (j == CLASS_space || j == CLASS_blank) {
 117                                         *buffer++ = '\t';
 118                                         if (j == CLASS_space) {
 119                                                 *buffer++ = '\n';
 120                                                 *buffer++ = '\v';
 121                                                 *buffer++ = '\f';
 122                                                 *buffer++ = '\r';
 123                                         }
 124                                         *buffer++ = ' ';
 125                                 }
 126                                 if (j == CLASS_punct || j == CLASS_cntrl) {
 127                                         for (i = '\0'; i <= ASCII; i++)
 128                                                 if ((j == CLASS_punct && isprint(i) && !isalnum(i) && !isspace(i))
 129                                                  || (j == CLASS_cntrl && iscntrl(i)))
 130                                                         *buffer++ = i;
 131                                 }
 132                                 if (j == CLASS_invalid) {
 133                                         *buffer++ = '[';
 134                                         *buffer++ = ':';
 135                                         continue;
 136                                 }
 137                                 break;
 138                         }
 139                         /* "[xyz...", i=x, arg points to y */
 140                         if (ENABLE_FEATURE_TR_EQUIV && i == '=') { /* [=CHAR=] */
 141                                 *buffer++ = *arg; /* copy CHAR */
 142                                 arg += 3;       /* skip CHAR=] */
 143                                 continue;
 144                         }
 145                         if (*arg != '-') { /* not [x-...] - copy verbatim */
 146                                 *buffer++ = '[';
 147                                 arg--; /* points to x */
 148                                 continue; /* copy all, including eventual ']' */
 149                         }
 150                         /* [x-y...] */
 151                         arg++;
 152                         ac = *arg++;
 153                         while (i <= ac)
 154                                 *buffer++ = i++;
 155                         arg++;  /* skip the assumed ']' */
 156                         continue;
 157                 }
 158                 *buffer++ = *arg++;
 159         }
 160         return (buffer - buffer_start);
 161 }
 162
 163 static int complement(char *buffer, int buffer_len)
 164 {
 165         int i, j, ix;
 166         char conv[ASCII + 2];
 167
 168         ix = 0;
 169         for (i = '\0'; i <= ASCII; i++) {
 170                 for (j = 0; j < buffer_len; j++)
 171                         if (buffer[j] == i)
 172                                 break;
 173                 if (j == buffer_len)
 174                         conv[ix++] = i & ASCII;
 175         }
 176         memcpy(buffer, conv, ix);
 177         return ix;
 178 }
 179
 180 int tr_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 181 int tr_main(int argc, char **argv)
 182 {
 183         unsigned char *ptr;
 184         int output_length = 0, input_length;
 185         int idx = 1;
 186         int i;
 187         smalluint flags = 0;
 188         ssize_t read_chars = 0;
 189         size_t in_index = 0, out_index = 0;
 190         unsigned last = UCHAR_MAX + 1; /* not equal to any char */
 191         unsigned char coded, c;
 192         RESERVE_CONFIG_UBUFFER(output, BUFSIZ);
 193         RESERVE_CONFIG_BUFFER(vector, ASCII+1);
 194         RESERVE_CONFIG_BUFFER(invec,  ASCII+1);
 195         RESERVE_CONFIG_BUFFER(outvec, ASCII+1);
 196
 197         if (argc > 1 && argv[idx][0] == '-') {
 198                 for (ptr = (unsigned char *) &argv[idx][1]; *ptr; ptr++) {
 199                         if (*ptr == 'c')
 200                                 flags |= TR_OPT_complement;
 201                         else if (*ptr == 'd')
 202                                 flags |= TR_OPT_delete;
 203                         else if (*ptr == 's')
 204                                 flags |= TR_OPT_squeeze_reps;
 205                         else
 206                                 bb_show_usage();
 207                 }
 208                 idx++;
 209         }
 210         for (i = 0; i <= ASCII; i++) {
 211                 vector[i] = i;
 212                 invec[i] = outvec[i] = FALSE;
 213         }
 214
 215 #define tr_buf bb_common_bufsiz1
 216         if (argv[idx] != NULL) {
 217                 input_length = expand(argv[idx++], tr_buf);
 218                 if (flags & TR_OPT_complement)
 219                         input_length = complement(tr_buf, input_length);
 220                 if (argv[idx]) {
 221                         if (argv[idx][0] == '\0')
 222                                 bb_error_msg_and_die("STRING2 cannot be empty");
 223                         output_length = expand(argv[idx], output);
 224                         map(vector, tr_buf, input_length, output, output_length);
 225                 }
 226                 for (i = 0; i < input_length; i++)
 227                         invec[(unsigned char)tr_buf[i]] = TRUE;
 228                 for (i = 0; i < output_length; i++)
 229                         outvec[output[i]] = TRUE;
 230         }
 231
 232         for (;;) {
 233                 /* If we're out of input, flush output and read more input. */
 234                 if (in_index == read_chars) {
 235                         if (out_index) {
 236                                 xwrite(STDOUT_FILENO, (char *)output, out_index);
 237                                 out_index = 0;
 238                         }
 239                         read_chars = safe_read(STDIN_FILENO, tr_buf, BUFSIZ);
 240                         if (read_chars <= 0) {
 241                                 if (read_chars < 0)
 242                                         bb_perror_msg_and_die(bb_msg_read_error);
 243                                 exit(EXIT_SUCCESS);
 244                         }
 245                         in_index = 0;
 246                 }
 247                 c = tr_buf[in_index++];
 248                 coded = vector[c];
 249                 if ((flags & TR_OPT_delete) && invec[c])
 250                         continue;
 251                 if ((flags & TR_OPT_squeeze_reps) && last == coded
 252                  && (invec[c] || outvec[coded]))
 253                         continue;
 254                 output[out_index++] = last = coded;
 255         }
 256         /* NOTREACHED */
 257         return EXIT_SUCCESS;
 258 }