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  *   Escapes, e.g.,  \a     ==>  Control-G
  47  *       Character classes, e.g. [:upper:] ==> A ... Z
  48  */
  49 static unsigned int expand(const char *arg, char *buffer)
  50 {
  51         char *buffer_start = buffer;
  52         unsigned i; /* XXX: FIXME: use unsigned char? */
  53         unsigned char ac;
  54 #define CLO ":]"
  55         static const char * const classes[] = {
  56                 "alpha"CLO, "alnum"CLO, "digit"CLO, "lower"CLO, "upper"CLO, "space"CLO,
  57                 "blank"CLO, "punct"CLO, "cntrl"CLO, NULL
  58         };
  59 #define CLASS_invalid 0 /* we increment the retval */
  60 #define CLASS_alpha 1
  61 #define CLASS_alnum 2
  62 #define CLASS_digit 3
  63 #define CLASS_lower 4
  64 #define CLASS_upper 5
  65 #define CLASS_space 6
  66 #define CLASS_blank 7
  67 #define CLASS_punct 8
  68 #define CLASS_cntrl 9
  69 //#define CLASS_xdigit 10
  70 //#define CLASS_graph 11
  71 //#define CLASS_print 12
  72         while (*arg) {
  73                 if (*arg == '\\') {
  74                         arg++;
  75                         *buffer++ = bb_process_escape_sequence(&arg);
  76                 } else if (*(arg+1) == '-') {
  77                         ac = *(arg+2);
  78                         if (ac == 0) {
  79                                 *buffer++ = *arg++;
  80                                 continue;
  81                         }
  82                         i = *arg;
  83                         while (i <= ac)
  84                                 *buffer++ = i++;
  85                         arg += 3; /* Skip the assumed a-z */
  86                 } else if (*arg == '[') {
  87                         arg++;
  88                         i = *arg++;
  89                         if (ENABLE_FEATURE_TR_CLASSES && i == ':') {
  90                                 smalluint j;
  91                                 { /* not really pretty.. */
  92                                         char *tmp = xstrndup(arg, 7); // warning: xdigit needs 8, not 7
  93                                         j = index_in_str_array(classes, tmp) + 1;
  94                                         free(tmp);
  95                                 }
  96                                 if (j == CLASS_alnum || j == CLASS_digit) {
  97                                         for (i = '0'; i <= '9'; i++)
  98                                                 *buffer++ = i;
  99                                 }
 100                                 if (j == CLASS_alpha || j == CLASS_alnum || j == CLASS_upper) {
 101                                         for (i = 'A'; i <= 'Z'; i++)
 102                                                 *buffer++ = i;
 103                                 }
 104                                 if (j == CLASS_alpha || j == CLASS_alnum || j == CLASS_lower) {
 105                                         for (i = 'a'; i <= 'z'; i++)
 106                                                 *buffer++ = i;
 107                                 }
 108                                 if (j == CLASS_space || j == CLASS_blank) {
 109                                         *buffer++ = '\t';
 110                                         if (j == CLASS_space) {
 111                                                 *buffer++ = '\n';
 112                                                 *buffer++ = '\v';
 113                                                 *buffer++ = '\f';
 114                                                 *buffer++ = '\r';
 115                                         }
 116                                         *buffer++ = ' ';
 117                                 }
 118                                 if (j == CLASS_punct || j == CLASS_cntrl) {
 119                                         for (i = 0; i <= ASCII; i++)
 120                                                 if ((j == CLASS_punct &&
 121                                                          isprint(i) && (!isalnum(i)) && (!isspace(i))) ||
 122                                                         (j == CLASS_cntrl && iscntrl(i)))
 123                                                         *buffer++ = i;
 124                                 }
 125                                 if (j == CLASS_invalid) {
 126                                         *buffer++ = '[';
 127                                         *buffer++ = ':';
 128                                         continue;
 129                                 }
 130                                 break;
 131                         }
 132                         if (ENABLE_FEATURE_TR_EQUIV && i == '=') {
 133                                 *buffer++ = *arg;
 134                                 arg += 3;       /* Skip the closing =] */
 135                                 continue;
 136                         }
 137                         if (*arg++ != '-') {
 138                                 *buffer++ = '[';
 139                                 arg -= 2;
 140                                 continue;
 141                         }
 142                         ac = *arg++;
 143                         while (i <= ac)
 144                                 *buffer++ = i++;
 145                         arg++;  /* Skip the assumed ']' */
 146                 } else
 147                         *buffer++ = *arg++;
 148         }
 149         return (buffer - buffer_start);
 150 }
 151
 152 static int complement(char *buffer, int buffer_len)
 153 {
 154         int i, j, ix;
 155         char conv[ASCII + 2];
 156
 157         ix = 0;
 158         for (i = 0; i <= ASCII; i++) {
 159                 for (j = 0; j < buffer_len; j++)
 160                         if (buffer[j] == i)
 161                                 break;
 162                 if (j == buffer_len)
 163                         conv[ix++] = i & ASCII;
 164         }
 165         memcpy(buffer, conv, ix);
 166         return ix;
 167 }
 168
 169 int tr_main(int argc, char **argv);
 170 int tr_main(int argc, char **argv)
 171 {
 172         unsigned char *ptr;
 173         int output_length = 0, input_length;
 174         int idx = 1;
 175         int i;
 176         smalluint flags = 0;
 177         size_t read_chars = 0, in_index = 0, out_index = 0, c, coded, last = -1;
 178         RESERVE_CONFIG_UBUFFER(output, BUFSIZ);
 179         RESERVE_CONFIG_BUFFER(vector, ASCII+1);
 180         RESERVE_CONFIG_BUFFER(invec,  ASCII+1);
 181         RESERVE_CONFIG_BUFFER(outvec, ASCII+1);
 182
 183         if (argc > 1 && argv[idx][0] == '-') {
 184                 for (ptr = (unsigned char *) &argv[idx][1]; *ptr; ptr++) {
 185                         if (*ptr == 'c')
 186                                 flags |= TR_OPT_complement;
 187                         else if (*ptr == 'd')
 188                                 flags |= TR_OPT_delete;
 189                         else if (*ptr == 's')
 190                                 flags |= TR_OPT_squeeze_reps;
 191                         else
 192                                 bb_show_usage();
 193                 }
 194                 idx++;
 195         }
 196         for (i = 0; i <= ASCII; i++) {
 197                 vector[i] = i;
 198                 invec[i] = outvec[i] = FALSE;
 199         }
 200
 201 #define tr_buf bb_common_bufsiz1
 202         if (argv[idx] != NULL) {
 203                 input_length = expand(argv[idx++], tr_buf);
 204                 if (flags & TR_OPT_complement)
 205                         input_length = complement(tr_buf, input_length);
 206                 if (argv[idx] != NULL) {
 207                         if (*argv[idx] == '\0')
 208                                 bb_error_msg_and_die("STRING2 cannot be empty");
 209                         output_length = expand(argv[idx], output);
 210                         map(vector, tr_buf, input_length, output, output_length);
 211                 }
 212                 for (i = 0; i < input_length; i++)
 213                         invec[(unsigned char)tr_buf[i]] = TRUE;
 214                 for (i = 0; i < output_length; i++)
 215                         outvec[output[i]] = TRUE;
 216         }
 217
 218         for (;;) {
 219                 /* If we're out of input, flush output and read more input. */
 220                 if (in_index == read_chars) {
 221                         if (out_index) {
 222                                 xwrite(STDOUT_FILENO, (char *)output, out_index);
 223                                 out_index = 0;
 224                         }
 225                         read_chars = read(STDIN_FILENO, tr_buf, BUFSIZ);
 226                         if (read_chars <= 0) {
 227                                 if (write(STDOUT_FILENO, (char *)output, out_index) != out_index)
 228                                         bb_perror_msg(bb_msg_write_error);
 229                                 exit(EXIT_SUCCESS);
 230                         }
 231                         in_index = 0;
 232                 }
 233                 c = tr_buf[in_index++];
 234                 coded = vector[c];
 235                 if ((flags & TR_OPT_delete) && invec[c])
 236                         continue;
 237                 if ((flags & TR_OPT_squeeze_reps) && last == coded &&
 238                         (invec[c] || outvec[coded]))
 239                         continue;
 240                 output[out_index++] = last = coded;
 241         }
 242         /* NOTREACHED */
 243         return EXIT_SUCCESS;
 244 }