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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//config:config TR
22//config: bool "tr"
23//config: default y
24//config: help
25//config: tr is used to squeeze, and/or delete characters from standard
26//config: input, writing to standard output.
27//config:
28//config:config FEATURE_TR_CLASSES
29//config: bool "Enable character classes (such as [:upper:])"
30//config: default y
31//config: depends on TR
32//config: help
33//config: Enable character classes, enabling commands such as:
34//config: tr [:upper:] [:lower:] to convert input into lowercase.
35//config:
36//config:config FEATURE_TR_EQUIV
37//config: bool "Enable equivalence classes"
38//config: default y
39//config: depends on TR
40//config: help
41//config: Enable equivalence classes, which essentially add the enclosed
42//config: character to the current set. For instance, tr [=a=] xyz would
43//config: replace all instances of 'a' with 'xyz'. This option is mainly
44//config: useful for cases when no other way of expressing a character
45//config: is possible.
46
47//applet:IF_TR(APPLET(tr, BB_DIR_USR_BIN, BB_SUID_DROP))
48
49//kbuild:lib-$(CONFIG_TR) += tr.o
50
51//usage:#define tr_trivial_usage
52//usage: "[-cds] STRING1 [STRING2]"
53//usage:#define tr_full_usage "\n\n"
54//usage: "Translate, squeeze, or delete characters from stdin, writing to stdout\n"
55//usage: "\n -c Take complement of STRING1"
56//usage: "\n -d Delete input characters coded STRING1"
57//usage: "\n -s Squeeze multiple output characters of STRING2 into one character"
58//usage:
59//usage:#define tr_example_usage
60//usage: "$ echo \"gdkkn vnqkc\" | tr [a-y] [b-z]\n"
61//usage: "hello world\n"
62
63#include "libbb.h"
64
65enum {
66 ASCII = 256,
67 /* string buffer needs to be at least as big as the whole "alphabet".
68 * BUFSIZ == ASCII is ok, but we will realloc in expand
69 * even for smallest patterns, let's avoid that by using *2:
70 */
71 TR_BUFSIZ = (BUFSIZ > ASCII*2) ? BUFSIZ : ASCII*2,
72};
73
74static void map(char *pvector,
75 char *string1, unsigned string1_len,
76 char *string2, unsigned string2_len)
77{
78 char last = '0';
79 unsigned i, j;
80
81 for (j = 0, i = 0; i < string1_len; i++) {
82 if (string2_len <= j)
83 pvector[(unsigned char)(string1[i])] = last;
84 else
85 pvector[(unsigned char)(string1[i])] = last = string2[j++];
86 }
87}
88
89/* supported constructs:
90 * Ranges, e.g., 0-9 ==> 0123456789
91 * Escapes, e.g., \a ==> Control-G
92 * Character classes, e.g. [:upper:] ==> A...Z
93 * Equiv classess, e.g. [=A=] ==> A (hmmmmmmm?)
94 * not supported:
95 * [x*N] - repeat char x N times
96 * [x*] - repeat char x until it fills STRING2:
97 * # echo qwe123 | /usr/bin/tr 123456789 '[d]'
98 * qwe[d]
99 * # echo qwe123 | /usr/bin/tr 123456789 '[d*]'
100 * qweddd
101 */
102static unsigned expand(char *arg, char **buffer_p)
103{
104 char *buffer = *buffer_p;
105 unsigned pos = 0;
106 unsigned size = TR_BUFSIZ;
107 unsigned i; /* can't be unsigned char: must be able to hold 256 */
108 unsigned char ac;
109
110 while (*arg) {
111 if (pos + ASCII > size) {
112 size += ASCII;
113 *buffer_p = buffer = xrealloc(buffer, size);
114 }
115 if (*arg == '\\') {
116 const char *z;
117 arg++;
118 z = arg;
119 ac = bb_process_escape_sequence(&z);
120 arg = (char *)z;
121 arg--;
122 *arg = ac;
123 /*
124 * fall through, there may be a range.
125 * If not, current char will be treated anyway.
126 */
127 }
128 if (arg[1] == '-') { /* "0-9..." */
129 ac = arg[2];
130 if (ac == '\0') { /* "0-": copy verbatim */
131 buffer[pos++] = *arg++; /* copy '0' */
132 continue; /* next iter will copy '-' and stop */
133 }
134 i = (unsigned char) *arg;
135 arg += 3; /* skip 0-9 or 0-\ */
136 if (ac == '\\') {
137 const char *z;
138 z = arg;
139 ac = bb_process_escape_sequence(&z);
140 arg = (char *)z;
141 }
142 while (i <= ac) /* ok: i is unsigned _int_ */
143 buffer[pos++] = i++;
144 continue;
145 }
146 if ((ENABLE_FEATURE_TR_CLASSES || ENABLE_FEATURE_TR_EQUIV)
147 && *arg == '['
148 ) {
149 arg++;
150 i = (unsigned char) *arg++;
151 /* "[xyz...". i=x, arg points to y */
152 if (ENABLE_FEATURE_TR_CLASSES && i == ':') { /* [:class:] */
153#define CLO ":]\0"
154 static const char classes[] ALIGN1 =
155 "alpha"CLO "alnum"CLO "digit"CLO
156 "lower"CLO "upper"CLO "space"CLO
157 "blank"CLO "punct"CLO "cntrl"CLO
158 "xdigit"CLO;
159 enum {
160 CLASS_invalid = 0, /* we increment the retval */
161 CLASS_alpha = 1,
162 CLASS_alnum = 2,
163 CLASS_digit = 3,
164 CLASS_lower = 4,
165 CLASS_upper = 5,
166 CLASS_space = 6,
167 CLASS_blank = 7,
168 CLASS_punct = 8,
169 CLASS_cntrl = 9,
170 CLASS_xdigit = 10,
171 //CLASS_graph = 11,
172 //CLASS_print = 12,
173 };
174 smalluint j;
175 char *tmp;
176
177 /* xdigit needs 8, not 7 */
178 i = 7 + (arg[0] == 'x');
179 tmp = xstrndup(arg, i);
180 j = index_in_strings(classes, tmp) + 1;
181 free(tmp);
182
183 if (j == CLASS_invalid)
184 goto skip_bracket;
185
186 arg += i;
187 if (j == CLASS_alnum || j == CLASS_digit || j == CLASS_xdigit) {
188 for (i = '0'; i <= '9'; i++)
189 buffer[pos++] = i;
190 }
191 if (j == CLASS_alpha || j == CLASS_alnum || j == CLASS_upper) {
192 for (i = 'A'; i <= 'Z'; i++)
193 buffer[pos++] = i;
194 }
195 if (j == CLASS_alpha || j == CLASS_alnum || j == CLASS_lower) {
196 for (i = 'a'; i <= 'z'; i++)
197 buffer[pos++] = i;
198 }
199 if (j == CLASS_space || j == CLASS_blank) {
200 buffer[pos++] = '\t';
201 if (j == CLASS_space) {
202 buffer[pos++] = '\n';
203 buffer[pos++] = '\v';
204 buffer[pos++] = '\f';
205 buffer[pos++] = '\r';
206 }
207 buffer[pos++] = ' ';
208 }
209 if (j == CLASS_punct || j == CLASS_cntrl) {
210 for (i = '\0'; i < ASCII; i++) {
211 if ((j == CLASS_punct && isprint_asciionly(i) && !isalnum(i) && !isspace(i))
212 || (j == CLASS_cntrl && iscntrl(i))
213 ) {
214 buffer[pos++] = i;
215 }
216 }
217 }
218 if (j == CLASS_xdigit) {
219 for (i = 'A'; i <= 'F'; i++) {
220 buffer[pos + 6] = i | 0x20;
221 buffer[pos++] = i;
222 }
223 pos += 6;
224 }
225 continue;
226 }
227 /* "[xyz...", i=x, arg points to y */
228 if (ENABLE_FEATURE_TR_EQUIV && i == '=') { /* [=CHAR=] */
229 buffer[pos++] = *arg; /* copy CHAR */
230 if (!arg[0] || arg[1] != '=' || arg[2] != ']')
231 bb_show_usage();
232 arg += 3; /* skip CHAR=] */
233 continue;
234 }
235 /* The rest of "[xyz..." cases is treated as normal
236 * string, "[" has no special meaning here:
237 * tr "[a-z]" "[A-Z]" can be written as tr "a-z" "A-Z",
238 * also try tr "[a-z]" "_A-Z+" and you'll see that
239 * [] is not special here.
240 */
241 skip_bracket:
242 arg -= 2; /* points to "[" in "[xyz..." */
243 }
244 buffer[pos++] = *arg++;
245 }
246 return pos;
247}
248
249/* NB: buffer is guaranteed to be at least TR_BUFSIZE
250 * (which is >= ASCII) big.
251 */
252static int complement(char *buffer, int buffer_len)
253{
254 int len;
255 char conv[ASCII];
256 unsigned char ch;
257
258 len = 0;
259 ch = '\0';
260 while (1) {
261 if (memchr(buffer, ch, buffer_len) == NULL)
262 conv[len++] = ch;
263 if (++ch == '\0')
264 break;
265 }
266 memcpy(buffer, conv, len);
267 return len;
268}
269
270int tr_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
271int tr_main(int argc UNUSED_PARAM, char **argv)
272{
273 int i;
274 smalluint opts;
275 ssize_t read_chars;
276 size_t in_index, out_index;
277 unsigned last = UCHAR_MAX + 1; /* not equal to any char */
278 unsigned char coded, c;
279 char *str1 = xmalloc(TR_BUFSIZ);
280 char *str2 = xmalloc(TR_BUFSIZ);
281 int str2_length;
282 int str1_length;
283 char *vector = xzalloc(ASCII * 3);
284 char *invec = vector + ASCII;
285 char *outvec = vector + ASCII * 2;
286
287#define TR_OPT_complement (3 << 0)
288#define TR_OPT_delete (1 << 2)
289#define TR_OPT_squeeze_reps (1 << 3)
290
291 for (i = 0; i < ASCII; i++) {
292 vector[i] = i;
293 /*invec[i] = outvec[i] = FALSE; - done by xzalloc */
294 }
295
296 /* -C/-c difference is that -C complements "characters",
297 * and -c complements "values" (binary bytes I guess).
298 * In POSIX locale, these are the same.
299 */
300
301 opt_complementary = "-1";
302 opts = getopt32(argv, "+Ccds"); /* '+': stop at first non-option */
303 argv += optind;
304
305 str1_length = expand(*argv++, &str1);
306 str2_length = 0;
307 if (opts & TR_OPT_complement)
308 str1_length = complement(str1, str1_length);
309 if (*argv) {
310 if (argv[0][0] == '\0')
311 bb_error_msg_and_die("STRING2 cannot be empty");
312 str2_length = expand(*argv, &str2);
313 map(vector, str1, str1_length,
314 str2, str2_length);
315 }
316 for (i = 0; i < str1_length; i++)
317 invec[(unsigned char)(str1[i])] = TRUE;
318 for (i = 0; i < str2_length; i++)
319 outvec[(unsigned char)(str2[i])] = TRUE;
320
321 goto start_from;
322
323 /* In this loop, str1 space is reused as input buffer,
324 * str2 - as output one. */
325 for (;;) {
326 /* If we're out of input, flush output and read more input. */
327 if ((ssize_t)in_index == read_chars) {
328 if (out_index) {
329 xwrite(STDOUT_FILENO, str2, out_index);
330 start_from:
331 out_index = 0;
332 }
333 read_chars = safe_read(STDIN_FILENO, str1, TR_BUFSIZ);
334 if (read_chars <= 0) {
335 if (read_chars < 0)
336 bb_perror_msg_and_die(bb_msg_read_error);
337 break;
338 }
339 in_index = 0;
340 }
341 c = str1[in_index++];
342 if ((opts & TR_OPT_delete) && invec[c])
343 continue;
344 coded = vector[c];
345 if ((opts & TR_OPT_squeeze_reps) && last == coded
346 && (invec[c] || outvec[coded])
347 ) {
348 continue;
349 }
350 str2[out_index++] = last = coded;
351 }
352
353 if (ENABLE_FEATURE_CLEAN_UP) {
354 free(vector);
355 free(str2);
356 free(str1);
357 }
358
359 return EXIT_SUCCESS;
360}
361
generated by cgit at 2024-05-15 06:14:27 (GMT)