blob: e3a07adf03922a21e2c81163fbdaeeb532a08597 [file] [log] [blame]
Denis Vlasenko687a26f2008-05-02 21:46:30 +00001/* 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 *
Denys Vlasenko0ef64bd2010-08-16 20:14:46 +02009 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
Denis Vlasenko687a26f2008-05-02 21:46:30 +000010 *
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>
Nicolas Hüppelshäuserb096ce02019-03-05 11:54:23 +010030#include <unistd.h>
Denis Vlasenko687a26f2008-05-02 21:46:30 +000031
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
38static 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
108int 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);
Denys Vlasenko0fcc7f52021-12-28 21:05:59 +0100156 } else
157 while ((c = *arg++) != '\0') {
158 if (c == eflag) {
159 /* This is an "\x" sequence */
160
Denis Vlasenko687a26f2008-05-02 21:46:30 +0000161 if (*arg == 'c') {
Denys Vlasenko0fcc7f52021-12-28 21:05:59 +0100162 /* "\c" means cancel newline and
Denis Vlasenko687a26f2008-05-02 21:46:30 +0000163 * ignore all subsequent chars. */
164 goto ret;
165 }
Denys Vlasenko0fcc7f52021-12-28 21:05:59 +0100166 /* Since SUSv3 mandates a first digit of 0, 4-digit octals
167 * of the form \0### are accepted. */
168 if (*arg == '0') {
169 if ((unsigned char)(arg[1] - '0') < 8) {
170 /* 2nd char is 0..7: skip leading '0' */
171 arg++;
Denis Vlasenko687a26f2008-05-02 21:46:30 +0000172 }
Denys Vlasenko0fcc7f52021-12-28 21:05:59 +0100173 }
174 /* bb_process_escape_sequence handles NUL correctly
175 * ("...\" case). */
176 {
177 /* optimization: don't force arg to be on-stack,
178 * use another variable for that. ~30 bytes win */
179 const char *z = arg;
180 c = bb_process_escape_sequence(&z);
181 arg = z;
Denis Vlasenko687a26f2008-05-02 21:46:30 +0000182 }
183 }
184 putchar(c);
185 }
186
187 arg = *++argv;
188 if (!arg)
189 break;
190 putchar(' ');
191 }
192
193 newline_ret:
194 if (nflag) {
195 putchar('\n');
196 }
197 ret:
Denys Vlasenkoda3a9562010-06-14 14:27:26 +0200198 return fflush(NULL);
Denis Vlasenko687a26f2008-05-02 21:46:30 +0000199}
200
201/*-
202 * Copyright (c) 1991, 1993
203 * The Regents of the University of California. All rights reserved.
204 *
205 * This code is derived from software contributed to Berkeley by
206 * Kenneth Almquist.
207 *
208 * Redistribution and use in source and binary forms, with or without
209 * modification, are permitted provided that the following conditions
210 * are met:
211 * 1. Redistributions of source code must retain the above copyright
212 * notice, this list of conditions and the following disclaimer.
213 * 2. Redistributions in binary form must reproduce the above copyright
214 * notice, this list of conditions and the following disclaimer in the
215 * documentation and/or other materials provided with the distribution.
216 *
217 * 3. <BSD Advertising Clause omitted per the July 22, 1999 licensing change
218 * ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change>
219 *
220 * California, Berkeley and its contributors.
221 * 4. Neither the name of the University nor the names of its contributors
222 * may be used to endorse or promote products derived from this software
223 * without specific prior written permission.
224 *
Denys Vlasenko95f79532017-08-02 14:26:33 +0200225 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND
Denis Vlasenko687a26f2008-05-02 21:46:30 +0000226 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
227 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
228 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
229 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
230 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
231 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
232 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
233 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
234 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
235 * SUCH DAMAGE.
236 *
237 * @(#)echo.c 8.1 (Berkeley) 5/31/93
238 */