1/* vi: set sw=4 ts=4: */
2/*
3 * Mini tr implementation for busybox
4 *
5 * Copyright (c) Michiel Huisjes
6 *
7 * This version of tr is adapted from Minix tr and was modified
8 * by Erik Andersen <andersee@debian.org> to be used in busybox.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 *
24 * Original copyright notice is retained at the end of this file.
25 */
26
27#include <stdio.h>
28#include <string.h>
29#include <stdlib.h>
30#include <unistd.h>
31#include <sys/types.h>
32#include "busybox.h"
33
34/* This must be a #define, since when DODEBUG and BUFFERS_GO_IN_BSS are
35 * enabled, we otherwise get a "storage size isn't constant error. */
36#define ASCII 0377
37
38/* some "globals" shared across this file */
39static char com_fl, del_fl, sq_fl;
40static short in_index, out_index;
41/* these last are pointers to static buffers declared in tr_main */
42static unsigned char *poutput, *pinput;
43static unsigned char *pvector;
44static char *pinvec, *poutvec;
45
46
47static void convert()
48{
49	short read_chars = 0;
50	short c, coded;
51	short last = -1;
52
53	for (;;) {
54		if (in_index == read_chars) {
55			if ((read_chars = read(0, (char *) pinput, BUFSIZ)) <= 0) {
56				if (write(1, (char *) poutput, out_index) != out_index)
57					error_msg("%s", write_error);
58				exit(0);
59			}
60			in_index = 0;
61		}
62		c = pinput[in_index++];
63		coded = pvector[c];
64		if (del_fl && pinvec[c])
65			continue;
66		if (sq_fl && last == coded && (pinvec[c] || poutvec[coded]))
67			continue;
68		poutput[out_index++] = last = coded;
69		if (out_index == BUFSIZ) {
70			if (write(1, (char *) poutput, out_index) != out_index)
71				error_msg_and_die("%s", write_error);
72			out_index = 0;
73		}
74	}
75
76	/* NOTREACHED */
77}
78
79static void map(register unsigned char *string1, unsigned int string1_len,
80		register unsigned char *string2, unsigned int string2_len)
81{
82	unsigned char last = '0';
83	unsigned int i, j;
84
85	for (j = 0, i = 0; i < string1_len; i++) {
86		if (string2_len <= j)
87			pvector[string1[i]] = last;
88		else
89			pvector[string1[i]] = last = string2[j++];
90	}
91}
92
93/* supported constructs:
94 *   Ranges,  e.g.,  [0-9]  ==>  0123456789
95 *   Escapes, e.g.,  \a     ==>  Control-G
96 */
97static unsigned int expand(const char *arg, register unsigned char *buffer)
98{
99	unsigned char *buffer_start = buffer;
100	int i, ac;
101
102	while (*arg) {
103		if (*arg == '\\') {
104			arg++;
105			*buffer++ = process_escape_sequence(&arg);
106		} else if (*(arg+1) == '-') {
107			ac = *(arg+2);
108			if(ac == 0) {
109				*buffer++ = *arg++;
110				continue;
111			}
112			i = *arg;
113			while (i <= ac)
114				*buffer++ = i++;
115			arg += 3; /* Skip the assumed a-z */
116		} else if (*arg == '[') {
117			arg++;
118			i = *arg++;
119			if (*arg++ != '-') {
120				*buffer++ = '[';
121				arg -= 2;
122				continue;
123			}
124			ac = *arg++;
125			while (i <= ac)
126				*buffer++ = i++;
127			arg++;				/* Skip the assumed ']' */
128		} else
129			*buffer++ = *arg++;
130	}
131
132	return (buffer - buffer_start);
133}
134
135static int complement(unsigned char *buffer, int buffer_len)
136{
137	register short i, j, ix;
138	char conv[ASCII + 2];
139
140	ix = 0;
141	for (i = 0; i <= ASCII; i++) {
142		for (j = 0; j < buffer_len; j++)
143			if (buffer[j] == i)
144				break;
145		if (j == buffer_len)
146			conv[ix++] = i & ASCII;
147	}
148	memcpy(buffer, conv, ix);
149	return ix;
150}
151
152extern int tr_main(int argc, char **argv)
153{
154	register unsigned char *ptr;
155	int output_length=0, input_length;
156	int idx = 1;
157	int i;
158	RESERVE_BB_BUFFER(output, BUFSIZ);
159	RESERVE_BB_BUFFER(input,  BUFSIZ);
160	RESERVE_BB_UBUFFER(vector, ASCII+1);
161	RESERVE_BB_BUFFER(invec,  ASCII+1);
162	RESERVE_BB_BUFFER(outvec, ASCII+1);
163
164	/* ... but make them available globally */
165	poutput = output;
166	pinput  = input;
167	pvector = vector;
168	pinvec  = invec;
169	poutvec = outvec;
170
171	if (argc > 1 && argv[idx][0] == '-') {
172		for (ptr = (unsigned char *) &argv[idx][1]; *ptr; ptr++) {
173			switch (*ptr) {
174			case 'c':
175				com_fl = TRUE;
176				break;
177			case 'd':
178				del_fl = TRUE;
179				break;
180			case 's':
181				sq_fl = TRUE;
182				break;
183			default:
184				show_usage();
185			}
186		}
187		idx++;
188	}
189	for (i = 0; i <= ASCII; i++) {
190		vector[i] = i;
191		invec[i] = outvec[i] = FALSE;
192	}
193
194	if (argv[idx] != NULL) {
195		input_length = expand(argv[idx++], input);
196		if (com_fl)
197			input_length = complement(input, input_length);
198		if (argv[idx] != NULL) {
199			if (*argv[idx] == '\0')
200				error_msg_and_die("STRING2 cannot be empty");
201			output_length = expand(argv[idx], output);
202			map(input, input_length, output, output_length);
203		}
204		for (i = 0; i < input_length; i++)
205			invec[(int)input[i]] = TRUE;
206		for (i = 0; i < output_length; i++)
207			outvec[(int)output[i]] = TRUE;
208	}
209	convert();
210	return (0);
211}
212
213/*
214 * Copyright (c) 1987,1997, Prentice Hall
215 * All rights reserved.
216 *
217 * Redistribution and use of the MINIX operating system in source and
218 * binary forms, with or without modification, are permitted provided
219 * that the following conditions are met:
220 *
221 * Redistributions of source code must retain the above copyright
222 * notice, this list of conditions and the following disclaimer.
223 *
224 * Redistributions in binary form must reproduce the above
225 * copyright notice, this list of conditions and the following
226 * disclaimer in the documentation and/or other materials provided
227 * with the distribution.
228 *
229 * Neither the name of Prentice Hall nor the names of the software
230 * authors or contributors may be used to endorse or promote
231 * products derived from this software without specific prior
232 * written permission.
233 *
234 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS, AUTHORS, AND
235 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
236 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
237 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
238 * IN NO EVENT SHALL PRENTICE HALL OR ANY AUTHORS OR CONTRIBUTORS BE
239 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
240 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
241 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
242 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
243 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
244 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
245 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
246 *
247 */
248
249