summaryrefslogtreecommitdiffhomepage
path: root/echo.c
blob: b31f2229bb784e9b3ff39ade751f51ff137c44b7 (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
/* 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.
 */

#include "internal.h"
#include <stdio.h>

static const char uname_usage[] =
	"echo [-neE] [ARG ...]\n"
#ifndef BB_FEATURE_TRIVIAL_HELP
	"\nPrints the specified ARGs to stdout\n\n"
	"Options:\n"
	"\t-n\tsuppress trailing newline\n"
	"\t-e\tinterpret backslash-escaped characters (i.e. \\t=tab etc)\n"
	"\t-E\tdisable interpretation of backslash-escaped characters\n"
#endif
	;

extern int 
echo_main(int argc, char** argv)
{
	register char **ap;
	register char *p;
	register char c;
	int nflag = 0;
	int eflag = 0;

	ap = argv;
	if (argc)
		ap++;
	while ((p = *ap) != NULL && *p == '-') {
		if (strcmp(p, "-n")==0) {
			nflag = 1;
		} else if (strcmp(p, "-e")==0) {
			eflag = 1;
		} else if (strcmp(p, "-E")==0) {
			eflag = 0;
		}
		else if (strncmp(p, "--", 2)==0) {
			usage( uname_usage);
		} 
		else break;
		ap++;
	}
	while ((p = *ap++) != NULL) {
		while ((c = *p++) != '\0') {
			if (c == '\\' && eflag) {
				switch (c = *p++) {
				case 'a':  c = '\007'; break;
				case 'b':  c = '\b';  break;
				case 'c':  exit( 0);		/* exit */
				case 'f':  c = '\f';  break;
				case 'n':  c = '\n';  break;
				case 'r':  c = '\r';  break;
				case 't':  c = '\t';  break;
				case 'v':  c = '\v';  break;
				case '\\':  break;		/* c = '\\' */
				case '0': case '1': case '2': case '3':
				case '4': case '5': case '6': case '7':
					c -= '0';
					if (*p >= '0' && *p <= '7')
						c = c * 8 + (*p++ - '0');
					if (*p >= '0' && *p <= '7')
					c = c * 8 + (*p++ - '0');
					break;
				default:
					p--;
					break;
				}
			}
			putchar(c);
		}
		if (*ap)
			putchar(' ');
	}
	if (! nflag)
		putchar('\n');
	fflush(stdout);
	exit( 0);
}

/*-
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	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
 */