1 /* vi: set sw=4 ts=4: */
2 /*
3 * echo implementation for busybox - used as a helper for testsuite/*
4 * on systems lacking "echo -en"
5 *
6 * Copyright (c) 1991, 1993
7 * The Regents of the University of California. All rights reserved.
8 *
9 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
10 *
11 * Original copyright notice is retained at the end of this file.
12 */
13
14 /* BB_AUDIT SUSv3 compliant -- unless configured as fancy echo. */
15 /* http://www.opengroup.org/onlinepubs/007904975/utilities/echo.html */
16
17 /* Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org)
18 *
19 * Because of behavioral differences, implemented configurable SUSv3
20 * or 'fancy' gnu-ish behaviors. Also, reduced size and fixed bugs.
21 * 1) In handling '\c' escape, the previous version only suppressed the
22 * trailing newline. SUSv3 specifies _no_ output after '\c'.
23 * 2) SUSv3 specifies that octal escapes are of the form \0{#{#{#}}}.
24 * The previous version did not allow 4-digit octals.
25 */
26
27 #include <stdio.h>
28 #include <string.h>
29 #include <limits.h>
30 #include <unistd.h>
31
32 #define WANT_HEX_ESCAPES 1
33
34 /* Usual "this only works for ascii compatible encodings" disclaimer. */
35 #undef _tolower
36 #define _tolower(X) ((X)|((char) 0x20))
37
bb_process_escape_sequence(const char ** ptr)38 static char bb_process_escape_sequence(const char **ptr)
39 {
40 static const char charmap[] = {
41 'a', 'b', 'f', 'n', 'r', 't', 'v', '\\', 0,
42 '\a', '\b', '\f', '\n', '\r', '\t', '\v', '\\', '\\' };
43
44 const char *p;
45 const char *q;
46 unsigned int num_digits;
47 unsigned int r;
48 unsigned int n;
49 unsigned int d;
50 unsigned int base;
51
52 num_digits = n = 0;
53 base = 8;
54 q = *ptr;
55
56 #ifdef WANT_HEX_ESCAPES
57 if (*q == 'x') {
58 ++q;
59 base = 16;
60 ++num_digits;
61 }
62 #endif
63
64 do {
65 d = (unsigned char)(*q) - '0';
66 #ifdef WANT_HEX_ESCAPES
67 if (d >= 10) {
68 d = (unsigned char)(_tolower(*q)) - 'a' + 10;
69 }
70 #endif
71
72 if (d >= base) {
73 #ifdef WANT_HEX_ESCAPES
74 if ((base == 16) && (!--num_digits)) {
75 /* return '\\'; */
76 --q;
77 }
78 #endif
79 break;
80 }
81
82 r = n * base + d;
83 if (r > UCHAR_MAX) {
84 break;
85 }
86
87 n = r;
88 ++q;
89 } while (++num_digits < 3);
90
91 if (num_digits == 0) { /* mnemonic escape sequence? */
92 p = charmap;
93 do {
94 if (*p == *q) {
95 q++;
96 break;
97 }
98 } while (*++p);
99 n = *(p + (sizeof(charmap)/2));
100 }
101
102 *ptr = q;
103
104 return (char) n;
105 }
106
107
main(int argc,char ** argv)108 int main(int argc, char **argv)
109 {
110 const char *arg;
111 const char *p;
112 char nflag = 1;
113 char eflag = 0;
114
115 /* We must check that stdout is not closed. */
116 if (dup2(1, 1) != 1)
117 return -1;
118
119 while (1) {
120 arg = *++argv;
121 if (!arg)
122 goto newline_ret;
123 if (*arg != '-')
124 break;
125
126 /* If it appears that we are handling options, then make sure
127 * that all of the options specified are actually valid.
128 * Otherwise, the string should just be echoed.
129 */
130 p = arg + 1;
131 if (!*p) /* A single '-', so echo it. */
132 goto just_echo;
133
134 do {
135 if (!strrchr("neE", *p))
136 goto just_echo;
137 } while (*++p);
138
139 /* All of the options in this arg are valid, so handle them. */
140 p = arg + 1;
141 do {
142 if (*p == 'n')
143 nflag = 0;
144 if (*p == 'e')
145 eflag = '\\';
146 } while (*++p);
147 }
148 just_echo:
149 while (1) {
150 /* arg is already == *argv and isn't NULL */
151 int c;
152
153 if (!eflag) {
154 /* optimization for very common case */
155 fputs(arg, stdout);
156 } else while ((c = *arg++)) {
157 if (c == eflag) { /* Check for escape seq. */
158 if (*arg == 'c') {
159 /* '\c' means cancel newline and
160 * ignore all subsequent chars. */
161 goto ret;
162 }
163 {
164 /* Since SUSv3 mandates a first digit of 0, 4-digit octals
165 * of the form \0### are accepted. */
166 if (*arg == '0') {
167 /* NB: don't turn "...\0" into "...\" */
168 if (arg[1] && ((unsigned char)(arg[1]) - '0') < 8) {
169 arg++;
170 }
171 }
172 /* bb_process_escape_sequence handles NUL correctly
173 * ("...\" case. */
174 c = bb_process_escape_sequence(&arg);
175 }
176 }
177 putchar(c);
178 }
179
180 arg = *++argv;
181 if (!arg)
182 break;
183 putchar(' ');
184 }
185
186 newline_ret:
187 if (nflag) {
188 putchar('\n');
189 }
190 ret:
191 return fflush(NULL);
192 }
193
194 /*-
195 * Copyright (c) 1991, 1993
196 * The Regents of the University of California. All rights reserved.
197 *
198 * This code is derived from software contributed to Berkeley by
199 * Kenneth Almquist.
200 *
201 * Redistribution and use in source and binary forms, with or without
202 * modification, are permitted provided that the following conditions
203 * are met:
204 * 1. Redistributions of source code must retain the above copyright
205 * notice, this list of conditions and the following disclaimer.
206 * 2. Redistributions in binary form must reproduce the above copyright
207 * notice, this list of conditions and the following disclaimer in the
208 * documentation and/or other materials provided with the distribution.
209 *
210 * 3. <BSD Advertising Clause omitted per the July 22, 1999 licensing change
211 * ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change>
212 *
213 * California, Berkeley and its contributors.
214 * 4. Neither the name of the University nor the names of its contributors
215 * may be used to endorse or promote products derived from this software
216 * without specific prior written permission.
217 *
218 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND
219 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
220 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
221 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
222 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
223 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
224 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
225 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
226 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
227 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
228 * SUCH DAMAGE.
229 *
230 * @(#)echo.c 8.1 (Berkeley) 5/31/93
231 */
232