tr: more of code shrink (getopt32-ification)
[people/mcb30/busybox.git] / 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 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                                 arg += 3;       /* skip CHAR=] */
139                                 continue;
140                         }
141                         if (*arg != '-') { /* not [x-...] - copy verbatim */
142                                 *buffer++ = '[';
143                                 arg--; /* points to x */
144                                 continue; /* copy all, including eventual ']' */
145                         }
146                         /* [x-y...] */
147                         arg++;
148                         ac = *arg++;
149                         while (i <= ac)
150                                 *buffer++ = i++;
151                         arg++;  /* skip the assumed ']' */
152                         continue;
153                 }
154                 *buffer++ = *arg++;
155         }
156         return (buffer - buffer_start);
157 }
158
159 static int complement(char *buffer, int buffer_len)
160 {
161         int i, j, ix;
162         char conv[ASCII + 2];
163
164         ix = 0;
165         for (i = '\0'; i <= ASCII; i++) {
166                 for (j = 0; j < buffer_len; j++)
167                         if (buffer[j] == i)
168                                 break;
169                 if (j == buffer_len)
170                         conv[ix++] = i & ASCII;
171         }
172         memcpy(buffer, conv, ix);
173         return ix;
174 }
175
176 int tr_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
177 int tr_main(int argc, char **argv)
178 {
179         int output_length = 0, input_length;
180         int i;
181         smalluint flags;
182         ssize_t read_chars = 0;
183         size_t in_index = 0, out_index = 0;
184         unsigned last = UCHAR_MAX + 1; /* not equal to any char */
185         unsigned char coded, c; 
186         unsigned char *output = xmalloc(BUFSIZ);
187         char *vector = xzalloc((ASCII+1) * 3);
188         char *invec  = vector + (ASCII+1);
189         char *outvec = vector + (ASCII+1) * 2;
190
191 #define TR_OPT_complement       (1 << 0)
192 #define TR_OPT_delete           (1 << 1)
193 #define TR_OPT_squeeze_reps     (1 << 2)
194
195         flags = getopt32(argv, "+cds"); /* '+': stop at first non-option */
196         argv += optind;
197
198         for (i = 0; i <= ASCII; i++) {
199                 vector[i] = i;
200                 /*invec[i] = outvec[i] = FALSE; - done by xzalloc */
201         }
202
203 #define tr_buf bb_common_bufsiz1
204         if (*argv != NULL) {
205                 input_length = expand(*argv++, tr_buf);
206                 if (flags & TR_OPT_complement)
207                         input_length = complement(tr_buf, input_length);
208                 if (*argv) {
209                         if (argv[0][0] == '\0')
210                                 bb_error_msg_and_die("STRING2 cannot be empty");
211                         output_length = expand(*argv, output);
212                         map(vector, tr_buf, input_length, output, output_length);
213                 }
214                 for (i = 0; i < input_length; i++)
215                         invec[(unsigned char)tr_buf[i]] = TRUE;
216                 for (i = 0; i < output_length; i++)
217                         outvec[output[i]] = TRUE;
218         }
219
220         for (;;) {
221                 /* If we're out of input, flush output and read more input. */
222                 if (in_index == read_chars) {
223                         if (out_index) {
224                                 xwrite(STDOUT_FILENO, (char *)output, out_index);
225                                 out_index = 0;
226                         }
227                         read_chars = safe_read(STDIN_FILENO, tr_buf, BUFSIZ);
228                         if (read_chars <= 0) {
229                                 if (read_chars < 0)
230                                         bb_perror_msg_and_die(bb_msg_read_error);
231                                 exit(EXIT_SUCCESS);
232                         }
233                         in_index = 0;
234                 }
235                 c = tr_buf[in_index++];
236                 coded = vector[c];
237                 if ((flags & TR_OPT_delete) && invec[c])
238                         continue;
239                 if ((flags & TR_OPT_squeeze_reps) && last == coded
240                  && (invec[c] || outvec[coded]))
241                         continue;
242                 output[out_index++] = last = coded;
243         }
244         /* NOTREACHED */
245         return EXIT_SUCCESS;
246 }