summaryrefslogtreecommitdiff
path: root/coreutils/echo.c
blob: 539640fb0052eb3d42f05324d8d05f706db86a15 (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
/* vi: set sw=4 ts=4: */
/*
 * echo implementation for busybox
 *
 * Copyright (c) 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Original copyright notice is retained at the end of this file.
 */

/* BB_AUDIT SUSv3 compliant -- unless configured as fancy echo. */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/echo.html */

/* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
 *
 * Because of behavioral differences, implemented configurable SUSv3
 * or 'fancy' gnu-ish behaviors.  Also, reduced size and fixed bugs.
 * 1) In handling '\c' escape, the previous version only suppressed the
 *     trailing newline.  SUSv3 specifies _no_ output after '\c'.
 * 2) SUSv3 specifies that octal escapes are of the form \0{#{#{#}}}.
 *    The previous version version did not allow 4-digit octals.
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "busybox.h"

extern int echo_main(int argc, char** argv)
{
#ifndef CONFIG_FEATURE_FANCY_ECHO
#define eflag '\\'
	++argv;
#else
	const char *p;
	int nflag = 1;
	int eflag = 0;

	while (*++argv && (**argv == '-')) {
		/* If it appears that we are handling options, then make sure
		 * that all of the options specified are actually valid.
		 * Otherwise, the string should just be echoed.
		 */

		if (!*(p = *argv + 1)) {	/* A single '-', so echo it. */
			goto just_echo;
		}

		do {
			if (strrchr("neE", *p) == 0) {
				goto just_echo;
			}
		} while (*++p);

		/* All of the options in this arg are valid, so handle them. */
		p = *argv + 1;
		do {
			if (*p == 'n') {
				nflag = 0;
			} else if (*p == 'e') {
				eflag = '\\';
			} else {
				eflag = 0;
			}
		} while (*++p);
	}

just_echo:
#endif
	while (*argv) {
		register int c;

		while ((c = *(*argv)++)) {
			if (c == eflag) {	/* Check for escape seq. */
				if (**argv == 'c') {
					/* '\c' means cancel newline and
					 * ignore all subsequent chars. */
					goto DONE;
				}
#ifndef CONFIG_FEATURE_FANCY_ECHO
				/* SUSv3 specifies that octal escapes must begin with '0'. */
				if (((unsigned int)(**argv - '1')) >= 7)
#endif
				{
					/* Since SUSv3 mandates a first digit of 0, 4-digit octals
					* of the form \0### are accepted. */
					if ((**argv == '0') && (((unsigned int)(argv[0][1] - '0')) < 8)) {
						(*argv)++;
					}
					/* bb_process_escape_sequence can handle nul correctly */
					c = bb_process_escape_sequence((const char **) argv);
				}
			}
			putchar(c);
		}

		if (*++argv) {
			putchar(' ');
		}
	}

#ifdef CONFIG_FEATURE_FANCY_ECHO
	if (nflag) {
		putchar('\n');
	}
#else
	putchar('\n');
#endif

DONE:
	bb_fflush_stdout_and_exit(EXIT_SUCCESS);
}

/*-
 * Copyright (c) 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. <BSD Advertising Clause omitted per the July 22, 1999 licensing change
 *		ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change>
 *
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)echo.c	8.1 (Berkeley) 5/31/93
 */