summaryrefslogtreecommitdiff
path: root/coreutils/tr.c
blob: e439fcb5b03a792a7b1385298e2acb374f90df5a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
/* vi: set sw=4 ts=4: */
/*
 * Mini tr implementation for busybox
 *
 ** Copyright (c) 1987,1997, Prentice Hall   All rights reserved.
 *
 * The name of Prentice Hall may not be used to endorse or promote
 * products derived from this software without specific prior
 * written permission.
 *
 * Copyright (c) Michiel Huisjes
 *
 * This version of tr is adapted from Minix tr and was modified
 * by Erik Andersen <andersen@codepoet.org> to be used in busybox.
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */
/* http://www.opengroup.org/onlinepubs/009695399/utilities/tr.html
 * TODO: xdigit, graph, print
 */
#include "libbb.h"

#define ASCII 0377

static void map(char *pvector,
		unsigned char *string1, unsigned int string1_len,
		unsigned char *string2, unsigned int string2_len)
{
	char last = '0';
	unsigned int i, j;

	for (j = 0, i = 0; i < string1_len; i++) {
		if (string2_len <= j)
			pvector[string1[i]] = last;
		else
			pvector[string1[i]] = last = string2[j++];
	}
}

/* supported constructs:
 *   Ranges,  e.g.,  0-9   ==>  0123456789
 *   Ranges,  e.g.,  [0-9] ==>  0123456789
 *   Escapes, e.g.,  \a    ==>  Control-G
 *   Character classes, e.g. [:upper:] ==> A...Z
 *   Equiv classess, e.g. [=A=] ==> A   (hmmmmmmm?)
 */
static unsigned int expand(const char *arg, char *buffer)
{
	char *buffer_start = buffer;
	unsigned i; /* can't be unsigned char: must be able to hold 256 */
	unsigned char ac;

	while (*arg) {
		if (*arg == '\\') {
			arg++;
			*buffer++ = bb_process_escape_sequence(&arg);
			continue;
		}
		if (arg[1] == '-') { /* "0-9..." */
			ac = arg[2];
			if (ac == '\0') { /* "0-": copy verbatim */
				*buffer++ = *arg++; /* copy '0' */
				continue; /* next iter will copy '-' and stop */
			}
			i = *arg;
			while (i <= ac) /* ok: i is unsigned _int_ */
				*buffer++ = i++;
			arg += 3; /* skip 0-9 */
			continue;
		}
		if (*arg == '[') { /* "[xyz..." */
			arg++;
			i = *arg++;
			/* "[xyz...", i=x, arg points to y */
			if (ENABLE_FEATURE_TR_CLASSES && i == ':') {
#define CLO ":]\0"
				static const char classes[] ALIGN1 =
					"alpha"CLO "alnum"CLO "digit"CLO
					"lower"CLO "upper"CLO "space"CLO
					"blank"CLO "punct"CLO "cntrl"CLO;
#define CLASS_invalid 0 /* we increment the retval */
#define CLASS_alpha 1
#define CLASS_alnum 2
#define CLASS_digit 3
#define CLASS_lower 4
#define CLASS_upper 5
#define CLASS_space 6
#define CLASS_blank 7
#define CLASS_punct 8
#define CLASS_cntrl 9
//#define CLASS_xdigit 10
//#define CLASS_graph 11
//#define CLASS_print 12
				smalluint j;
				{ /* not really pretty.. */
					char *tmp = xstrndup(arg, 7); // warning: xdigit would need 8, not 7
					j = index_in_strings(classes, tmp) + 1;
					free(tmp);
				}
				if (j == CLASS_alnum || j == CLASS_digit) {
					for (i = '0'; i <= '9'; i++)
						*buffer++ = i;
				}
				if (j == CLASS_alpha || j == CLASS_alnum || j == CLASS_upper) {
					for (i = 'A'; i <= 'Z'; i++)
						*buffer++ = i;
				}
				if (j == CLASS_alpha || j == CLASS_alnum || j == CLASS_lower) {
					for (i = 'a'; i <= 'z'; i++)
						*buffer++ = i;
				}
				if (j == CLASS_space || j == CLASS_blank) {
					*buffer++ = '\t';
					if (j == CLASS_space) {
						*buffer++ = '\n';
						*buffer++ = '\v';
						*buffer++ = '\f';
						*buffer++ = '\r';
					}
					*buffer++ = ' ';
				}
				if (j == CLASS_punct || j == CLASS_cntrl) {
					for (i = '\0'; i <= ASCII; i++)
						if ((j == CLASS_punct && isprint(i) && !isalnum(i) && !isspace(i))
						 || (j == CLASS_cntrl && iscntrl(i)))
							*buffer++ = i;
				}
				if (j == CLASS_invalid) {
					*buffer++ = '[';
					*buffer++ = ':';
					continue;
				}
				break;
			}
			/* "[xyz...", i=x, arg points to y */
			if (ENABLE_FEATURE_TR_EQUIV && i == '=') { /* [=CHAR=] */
				*buffer++ = *arg; /* copy CHAR */
				arg += 3;	/* skip CHAR=] */
				continue;
			}
			if (*arg != '-') { /* not [x-...] - copy verbatim */
				*buffer++ = '[';
				arg--; /* points to x */
				continue; /* copy all, including eventual ']' */
			}
			/* [x-y...] */
			arg++;
			ac = *arg++;
			while (i <= ac)
				*buffer++ = i++;
			arg++;	/* skip the assumed ']' */
			continue;
		}
		*buffer++ = *arg++;
	}
	return (buffer - buffer_start);
}

static int complement(char *buffer, int buffer_len)
{
	int i, j, ix;
	char conv[ASCII + 2];

	ix = 0;
	for (i = '\0'; i <= ASCII; i++) {
		for (j = 0; j < buffer_len; j++)
			if (buffer[j] == i)
				break;
		if (j == buffer_len)
			conv[ix++] = i & ASCII;
	}
	memcpy(buffer, conv, ix);
	return ix;
}

int tr_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int tr_main(int argc UNUSED_PARAM, char **argv)
{
	int output_length = 0, input_length;
	int i;
	smalluint flags;
	ssize_t read_chars = 0;
	size_t in_index = 0, out_index = 0;
	unsigned last = UCHAR_MAX + 1; /* not equal to any char */
	unsigned char coded, c;
	unsigned char *output = xmalloc(BUFSIZ);
	char *vector = xzalloc((ASCII+1) * 3);
	char *invec  = vector + (ASCII+1);
	char *outvec = vector + (ASCII+1) * 2;

#define TR_OPT_complement	(1 << 0)
#define TR_OPT_delete		(1 << 1)
#define TR_OPT_squeeze_reps	(1 << 2)

	flags = getopt32(argv, "+cds"); /* '+': stop at first non-option */
	argv += optind;

	for (i = 0; i <= ASCII; i++) {
		vector[i] = i;
		/*invec[i] = outvec[i] = FALSE; - done by xzalloc */
	}

#define tr_buf bb_common_bufsiz1
	if (*argv != NULL) {
		input_length = expand(*argv++, tr_buf);
		if (flags & TR_OPT_complement)
			input_length = complement(tr_buf, input_length);
		if (*argv) {
			if (argv[0][0] == '\0')
				bb_error_msg_and_die("STRING2 cannot be empty");
			output_length = expand(*argv, (char *)output);
			map(vector, (unsigned char *)tr_buf, input_length, output, output_length);
		}
		for (i = 0; i < input_length; i++)
			invec[(unsigned char)tr_buf[i]] = TRUE;
		for (i = 0; i < output_length; i++)
			outvec[output[i]] = TRUE;
	}

	for (;;) {
		/* If we're out of input, flush output and read more input. */
		if ((ssize_t)in_index == read_chars) {
			if (out_index) {
				xwrite(STDOUT_FILENO, (char *)output, out_index);
				out_index = 0;
			}
			read_chars = safe_read(STDIN_FILENO, tr_buf, BUFSIZ);
			if (read_chars <= 0) {
				if (read_chars < 0)
					bb_perror_msg_and_die(bb_msg_read_error);
				exit(EXIT_SUCCESS);
			}
			in_index = 0;
		}
		c = tr_buf[in_index++];
		coded = vector[c];
		if ((flags & TR_OPT_delete) && invec[c])
			continue;
		if ((flags & TR_OPT_squeeze_reps) && last == coded
		 && (invec[c] || outvec[coded]))
			continue;
		output[out_index++] = last = coded;
	}
	/* NOTREACHED */
	return EXIT_SUCCESS;
}