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Contents of /tags/mkinitrd-6_1_5/busybox/coreutils/tr.c

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Revision 899 - (show annotations) (download)
Wed Aug 5 17:52:52 2009 UTC (14 years, 10 months ago) by niro
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tagged 'mkinitrd-6_1_5'
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 static void map(char *pvector,
26 unsigned char *string1, unsigned int string1_len,
27 unsigned char *string2, unsigned int string2_len)
28 {
29 char last = '0';
30 unsigned int i, j;
31
32 for (j = 0, i = 0; i < string1_len; i++) {
33 if (string2_len <= j)
34 pvector[string1[i]] = last;
35 else
36 pvector[string1[i]] = last = string2[j++];
37 }
38 }
39
40 /* supported constructs:
41 * Ranges, e.g., 0-9 ==> 0123456789
42 * Ranges, e.g., [0-9] ==> 0123456789
43 * Escapes, e.g., \a ==> Control-G
44 * Character classes, e.g. [:upper:] ==> A...Z
45 * Equiv classess, e.g. [=A=] ==> A (hmmmmmmm?)
46 */
47 static unsigned int expand(const char *arg, char *buffer)
48 {
49 char *buffer_start = buffer;
50 unsigned i; /* can't be unsigned char: must be able to hold 256 */
51 unsigned char ac;
52
53 while (*arg) {
54 if (*arg == '\\') {
55 arg++;
56 *buffer++ = bb_process_escape_sequence(&arg);
57 continue;
58 }
59 if (arg[1] == '-') { /* "0-9..." */
60 ac = arg[2];
61 if (ac == '\0') { /* "0-": copy verbatim */
62 *buffer++ = *arg++; /* copy '0' */
63 continue; /* next iter will copy '-' and stop */
64 }
65 i = *arg;
66 while (i <= ac) /* ok: i is unsigned _int_ */
67 *buffer++ = i++;
68 arg += 3; /* skip 0-9 */
69 continue;
70 }
71 if (*arg == '[') { /* "[xyz..." */
72 arg++;
73 i = *arg++;
74 /* "[xyz...", i=x, arg points to y */
75 if (ENABLE_FEATURE_TR_CLASSES && i == ':') {
76 #define CLO ":]\0"
77 static const char classes[] ALIGN1 =
78 "alpha"CLO "alnum"CLO "digit"CLO
79 "lower"CLO "upper"CLO "space"CLO
80 "blank"CLO "punct"CLO "cntrl"CLO;
81 #define CLASS_invalid 0 /* we increment the retval */
82 #define CLASS_alpha 1
83 #define CLASS_alnum 2
84 #define CLASS_digit 3
85 #define CLASS_lower 4
86 #define CLASS_upper 5
87 #define CLASS_space 6
88 #define CLASS_blank 7
89 #define CLASS_punct 8
90 #define CLASS_cntrl 9
91 //#define CLASS_xdigit 10
92 //#define CLASS_graph 11
93 //#define CLASS_print 12
94 smalluint j;
95 { /* not really pretty.. */
96 char *tmp = xstrndup(arg, 7); // warning: xdigit would need 8, not 7
97 j = index_in_strings(classes, tmp) + 1;
98 free(tmp);
99 }
100 if (j == CLASS_alnum || j == CLASS_digit) {
101 for (i = '0'; i <= '9'; i++)
102 *buffer++ = i;
103 }
104 if (j == CLASS_alpha || j == CLASS_alnum || j == CLASS_upper) {
105 for (i = 'A'; i <= 'Z'; i++)
106 *buffer++ = i;
107 }
108 if (j == CLASS_alpha || j == CLASS_alnum || j == CLASS_lower) {
109 for (i = 'a'; i <= 'z'; i++)
110 *buffer++ = i;
111 }
112 if (j == CLASS_space || j == CLASS_blank) {
113 *buffer++ = '\t';
114 if (j == CLASS_space) {
115 *buffer++ = '\n';
116 *buffer++ = '\v';
117 *buffer++ = '\f';
118 *buffer++ = '\r';
119 }
120 *buffer++ = ' ';
121 }
122 if (j == CLASS_punct || j == CLASS_cntrl) {
123 for (i = '\0'; i <= ASCII; i++)
124 if ((j == CLASS_punct && isprint(i) && !isalnum(i) && !isspace(i))
125 || (j == CLASS_cntrl && iscntrl(i)))
126 *buffer++ = i;
127 }
128 if (j == CLASS_invalid) {
129 *buffer++ = '[';
130 *buffer++ = ':';
131 continue;
132 }
133 break;
134 }
135 /* "[xyz...", i=x, arg points to y */
136 if (ENABLE_FEATURE_TR_EQUIV && i == '=') { /* [=CHAR=] */
137 *buffer++ = *arg; /* copy CHAR */
138 if (!*arg || arg[1] != '=' || arg[2] != ']')
139 bb_show_usage();
140 arg += 3; /* skip CHAR=] */
141 continue;
142 }
143 if (i == '\0' || *arg != '-') { /* not [x-...] - copy verbatim */
144 *buffer++ = '[';
145 arg--; /* points to x */
146 continue; /* copy all, including eventual ']' */
147 }
148 /* [x-z] */
149 arg++; /* skip - */
150 if (arg[0] == '\0' || arg[1] != ']')
151 bb_show_usage();
152 ac = *arg++;
153 while (i <= ac)
154 *buffer++ = i++;
155 arg++; /* skip ] */
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 UNUSED_PARAM, char **argv)
182 {
183 int output_length = 0, input_length;
184 int i;
185 smalluint flags;
186 ssize_t read_chars = 0;
187 size_t in_index = 0, out_index = 0;
188 unsigned last = UCHAR_MAX + 1; /* not equal to any char */
189 unsigned char coded, c;
190 unsigned char *output = xmalloc(BUFSIZ);
191 char *vector = xzalloc((ASCII+1) * 3);
192 char *invec = vector + (ASCII+1);
193 char *outvec = vector + (ASCII+1) * 2;
194
195 #define TR_OPT_complement (1 << 0)
196 #define TR_OPT_delete (1 << 1)
197 #define TR_OPT_squeeze_reps (1 << 2)
198
199 flags = getopt32(argv, "+cds"); /* '+': stop at first non-option */
200 argv += optind;
201
202 for (i = 0; i <= ASCII; i++) {
203 vector[i] = i;
204 /*invec[i] = outvec[i] = FALSE; - done by xzalloc */
205 }
206
207 #define tr_buf bb_common_bufsiz1
208 if (*argv != NULL) {
209 input_length = expand(*argv++, tr_buf);
210 if (flags & TR_OPT_complement)
211 input_length = complement(tr_buf, input_length);
212 if (*argv) {
213 if (argv[0][0] == '\0')
214 bb_error_msg_and_die("STRING2 cannot be empty");
215 output_length = expand(*argv, (char *)output);
216 map(vector, (unsigned char *)tr_buf, input_length, output, output_length);
217 }
218 for (i = 0; i < input_length; i++)
219 invec[(unsigned char)tr_buf[i]] = TRUE;
220 for (i = 0; i < output_length; i++)
221 outvec[output[i]] = TRUE;
222 }
223
224 for (;;) {
225 /* If we're out of input, flush output and read more input. */
226 if ((ssize_t)in_index == read_chars) {
227 if (out_index) {
228 xwrite(STDOUT_FILENO, (char *)output, out_index);
229 out_index = 0;
230 }
231 read_chars = safe_read(STDIN_FILENO, tr_buf, BUFSIZ);
232 if (read_chars <= 0) {
233 if (read_chars < 0)
234 bb_perror_msg_and_die(bb_msg_read_error);
235 exit(EXIT_SUCCESS);
236 }
237 in_index = 0;
238 }
239 c = tr_buf[in_index++];
240 coded = vector[c];
241 if ((flags & TR_OPT_delete) && invec[c])
242 continue;
243 if ((flags & TR_OPT_squeeze_reps) && last == coded
244 && (invec[c] || outvec[coded]))
245 continue;
246 output[out_index++] = last = coded;
247 }
248 /* NOTREACHED */
249 return EXIT_SUCCESS;
250 }