source: MondoRescue/branches/2.2.9/mindi-busybox/coreutils/tr.c@ 3320

Last change on this file since 3320 was 3320, checked in by Bruno Cornec, 9 years ago
  • Re-add (thanks git BTW) the 2.2.9 branch which had been destroyed in the move to 3.0
  • Property svn:eol-style set to native
File size: 8.7 KB
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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 source tree.
17 */
18/* http://www.opengroup.org/onlinepubs/009695399/utilities/tr.html
19 * TODO: graph, print
20 */
21
22//kbuild:lib-$(CONFIG_TR) += tr.o
23
24//config:config TR
25//config: bool "tr"
26//config: default y
27//config: help
28//config: tr is used to squeeze, and/or delete characters from standard
29//config: input, writing to standard output.
30//config:
31//config:config FEATURE_TR_CLASSES
32//config: bool "Enable character classes (such as [:upper:])"
33//config: default y
34//config: depends on TR
35//config: help
36//config: Enable character classes, enabling commands such as:
37//config: tr [:upper:] [:lower:] to convert input into lowercase.
38//config:
39//config:config FEATURE_TR_EQUIV
40//config: bool "Enable equivalence classes"
41//config: default y
42//config: depends on TR
43//config: help
44//config: Enable equivalence classes, which essentially add the enclosed
45//config: character to the current set. For instance, tr [=a=] xyz would
46//config: replace all instances of 'a' with 'xyz'. This option is mainly
47//config: useful for cases when no other way of expressing a character
48//config: is possible.
49
50#include "libbb.h"
51
52enum {
53 ASCII = 256,
54 /* string buffer needs to be at least as big as the whole "alphabet".
55 * BUFSIZ == ASCII is ok, but we will realloc in expand
56 * even for smallest patterns, let's avoid that by using *2:
57 */
58 TR_BUFSIZ = (BUFSIZ > ASCII*2) ? BUFSIZ : ASCII*2,
59};
60
61static void map(char *pvector,
62 char *string1, unsigned string1_len,
63 char *string2, unsigned string2_len)
64{
65 char last = '0';
66 unsigned i, j;
67
68 for (j = 0, i = 0; i < string1_len; i++) {
69 if (string2_len <= j)
70 pvector[(unsigned char)(string1[i])] = last;
71 else
72 pvector[(unsigned char)(string1[i])] = last = string2[j++];
73 }
74}
75
76/* supported constructs:
77 * Ranges, e.g., 0-9 ==> 0123456789
78 * Escapes, e.g., \a ==> Control-G
79 * Character classes, e.g. [:upper:] ==> A...Z
80 * Equiv classess, e.g. [=A=] ==> A (hmmmmmmm?)
81 * not supported:
82 * \ooo-\ooo - octal ranges
83 * [x*N] - repeat char x N times
84 * [x*] - repeat char x until it fills STRING2:
85 * # echo qwe123 | /usr/bin/tr 123456789 '[d]'
86 * qwe[d]
87 * # echo qwe123 | /usr/bin/tr 123456789 '[d*]'
88 * qweddd
89 */
90static unsigned expand(const char *arg, char **buffer_p)
91{
92 char *buffer = *buffer_p;
93 unsigned pos = 0;
94 unsigned size = TR_BUFSIZ;
95 unsigned i; /* can't be unsigned char: must be able to hold 256 */
96 unsigned char ac;
97
98 while (*arg) {
99 if (pos + ASCII > size) {
100 size += ASCII;
101 *buffer_p = buffer = xrealloc(buffer, size);
102 }
103 if (*arg == '\\') {
104 arg++;
105 buffer[pos++] = bb_process_escape_sequence(&arg);
106 continue;
107 }
108 if (arg[1] == '-') { /* "0-9..." */
109 ac = arg[2];
110 if (ac == '\0') { /* "0-": copy verbatim */
111 buffer[pos++] = *arg++; /* copy '0' */
112 continue; /* next iter will copy '-' and stop */
113 }
114 i = (unsigned char) *arg;
115 while (i <= ac) /* ok: i is unsigned _int_ */
116 buffer[pos++] = i++;
117 arg += 3; /* skip 0-9 */
118 continue;
119 }
120 if ((ENABLE_FEATURE_TR_CLASSES || ENABLE_FEATURE_TR_EQUIV)
121 && *arg == '['
122 ) {
123 arg++;
124 i = (unsigned char) *arg++;
125 /* "[xyz...". i=x, arg points to y */
126 if (ENABLE_FEATURE_TR_CLASSES && i == ':') { /* [:class:] */
127#define CLO ":]\0"
128 static const char classes[] ALIGN1 =
129 "alpha"CLO "alnum"CLO "digit"CLO
130 "lower"CLO "upper"CLO "space"CLO
131 "blank"CLO "punct"CLO "cntrl"CLO
132 "xdigit"CLO;
133 enum {
134 CLASS_invalid = 0, /* we increment the retval */
135 CLASS_alpha = 1,
136 CLASS_alnum = 2,
137 CLASS_digit = 3,
138 CLASS_lower = 4,
139 CLASS_upper = 5,
140 CLASS_space = 6,
141 CLASS_blank = 7,
142 CLASS_punct = 8,
143 CLASS_cntrl = 9,
144 CLASS_xdigit = 10,
145 //CLASS_graph = 11,
146 //CLASS_print = 12,
147 };
148 smalluint j;
149 char *tmp;
150
151 /* xdigit needs 8, not 7 */
152 i = 7 + (arg[0] == 'x');
153 tmp = xstrndup(arg, i);
154 j = index_in_strings(classes, tmp) + 1;
155 free(tmp);
156
157 if (j == CLASS_invalid)
158 goto skip_bracket;
159
160 arg += i;
161 if (j == CLASS_alnum || j == CLASS_digit || j == CLASS_xdigit) {
162 for (i = '0'; i <= '9'; i++)
163 buffer[pos++] = i;
164 }
165 if (j == CLASS_alpha || j == CLASS_alnum || j == CLASS_upper) {
166 for (i = 'A'; i <= 'Z'; i++)
167 buffer[pos++] = i;
168 }
169 if (j == CLASS_alpha || j == CLASS_alnum || j == CLASS_lower) {
170 for (i = 'a'; i <= 'z'; i++)
171 buffer[pos++] = i;
172 }
173 if (j == CLASS_space || j == CLASS_blank) {
174 buffer[pos++] = '\t';
175 if (j == CLASS_space) {
176 buffer[pos++] = '\n';
177 buffer[pos++] = '\v';
178 buffer[pos++] = '\f';
179 buffer[pos++] = '\r';
180 }
181 buffer[pos++] = ' ';
182 }
183 if (j == CLASS_punct || j == CLASS_cntrl) {
184 for (i = '\0'; i < ASCII; i++) {
185 if ((j == CLASS_punct && isprint_asciionly(i) && !isalnum(i) && !isspace(i))
186 || (j == CLASS_cntrl && iscntrl(i))
187 ) {
188 buffer[pos++] = i;
189 }
190 }
191 }
192 if (j == CLASS_xdigit) {
193 for (i = 'A'; i <= 'F'; i++) {
194 buffer[pos + 6] = i | 0x20;
195 buffer[pos++] = i;
196 }
197 pos += 6;
198 }
199 continue;
200 }
201 /* "[xyz...", i=x, arg points to y */
202 if (ENABLE_FEATURE_TR_EQUIV && i == '=') { /* [=CHAR=] */
203 buffer[pos++] = *arg; /* copy CHAR */
204 if (!arg[0] || arg[1] != '=' || arg[2] != ']')
205 bb_show_usage();
206 arg += 3; /* skip CHAR=] */
207 continue;
208 }
209 /* The rest of "[xyz..." cases is treated as normal
210 * string, "[" has no special meaning here:
211 * tr "[a-z]" "[A-Z]" can be written as tr "a-z" "A-Z",
212 * also try tr "[a-z]" "_A-Z+" and you'll see that
213 * [] is not special here.
214 */
215 skip_bracket:
216 arg -= 2; /* points to "[" in "[xyz..." */
217 }
218 buffer[pos++] = *arg++;
219 }
220 return pos;
221}
222
223/* NB: buffer is guaranteed to be at least TR_BUFSIZE
224 * (which is >= ASCII) big.
225 */
226static int complement(char *buffer, int buffer_len)
227{
228 int len;
229 char conv[ASCII];
230 unsigned char ch;
231
232 len = 0;
233 ch = '\0';
234 while (1) {
235 if (memchr(buffer, ch, buffer_len) == NULL)
236 conv[len++] = ch;
237 if (++ch == '\0')
238 break;
239 }
240 memcpy(buffer, conv, len);
241 return len;
242}
243
244int tr_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
245int tr_main(int argc UNUSED_PARAM, char **argv)
246{
247 int i;
248 smalluint opts;
249 ssize_t read_chars;
250 size_t in_index, out_index;
251 unsigned last = UCHAR_MAX + 1; /* not equal to any char */
252 unsigned char coded, c;
253 char *str1 = xmalloc(TR_BUFSIZ);
254 char *str2 = xmalloc(TR_BUFSIZ);
255 int str2_length;
256 int str1_length;
257 char *vector = xzalloc(ASCII * 3);
258 char *invec = vector + ASCII;
259 char *outvec = vector + ASCII * 2;
260
261#define TR_OPT_complement (3 << 0)
262#define TR_OPT_delete (1 << 2)
263#define TR_OPT_squeeze_reps (1 << 3)
264
265 for (i = 0; i < ASCII; i++) {
266 vector[i] = i;
267 /*invec[i] = outvec[i] = FALSE; - done by xzalloc */
268 }
269
270 /* -C/-c difference is that -C complements "characters",
271 * and -c complements "values" (binary bytes I guess).
272 * In POSIX locale, these are the same.
273 */
274
275 opt_complementary = "-1";
276 opts = getopt32(argv, "+Ccds"); /* '+': stop at first non-option */
277 argv += optind;
278
279 str1_length = expand(*argv++, &str1);
280 str2_length = 0;
281 if (opts & TR_OPT_complement)
282 str1_length = complement(str1, str1_length);
283 if (*argv) {
284 if (argv[0][0] == '\0')
285 bb_error_msg_and_die("STRING2 cannot be empty");
286 str2_length = expand(*argv, &str2);
287 map(vector, str1, str1_length,
288 str2, str2_length);
289 }
290 for (i = 0; i < str1_length; i++)
291 invec[(unsigned char)(str1[i])] = TRUE;
292 for (i = 0; i < str2_length; i++)
293 outvec[(unsigned char)(str2[i])] = TRUE;
294
295 goto start_from;
296
297 /* In this loop, str1 space is reused as input buffer,
298 * str2 - as output one. */
299 for (;;) {
300 /* If we're out of input, flush output and read more input. */
301 if ((ssize_t)in_index == read_chars) {
302 if (out_index) {
303 xwrite(STDOUT_FILENO, str2, out_index);
304 start_from:
305 out_index = 0;
306 }
307 read_chars = safe_read(STDIN_FILENO, str1, TR_BUFSIZ);
308 if (read_chars <= 0) {
309 if (read_chars < 0)
310 bb_perror_msg_and_die(bb_msg_read_error);
311 break;
312 }
313 in_index = 0;
314 }
315 c = str1[in_index++];
316 if ((opts & TR_OPT_delete) && invec[c])
317 continue;
318 coded = vector[c];
319 if ((opts & TR_OPT_squeeze_reps) && last == coded
320 && (invec[c] || outvec[coded])
321 ) {
322 continue;
323 }
324 str2[out_index++] = last = coded;
325 }
326
327 return EXIT_SUCCESS;
328}
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