1 /* $NetBSD: echo.c,v 1.12 2005/02/06 04:43:43 perry Exp $ */
2
3 /*-
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Kenneth Almquist.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)echo.c 8.1 (Berkeley) 5/31/93
35 */
36
37 /*
38 * Echo command.
39 *
40 * echo is steeped in tradition - several of them!
41 * netbsd has supported 'echo [-n | -e] args' in spite of -e not being
42 * documented anywhere.
43 * Posix requires that -n be supported, output from strings containing
44 * \ is implementation defined
45 * The Single Unix Spec requires that \ escapes be treated as if -e
46 * were set, but that -n not be treated as an option.
47 * (ksh supports 'echo [-eEn] args', but not -- so that it is actually
48 * impossible to actually output '-n')
49 *
50 * It is suggested that 'printf "%b" "string"' be used to get \ sequences
51 * expanded. printf is now a builtin of netbsd's sh and csh.
52 */
53
54 //#define main echocmd
55
56 #include "bltin.h"
57
58 int
echocmd(int argc,char ** argv)59 echocmd(int argc, char **argv)
60 {
61 char **ap;
62 char *p;
63 char c;
64 int count;
65 int nflag = 0;
66 int eflag = 0;
67
68 ap = argv;
69 if (argc)
70 ap++;
71
72 if ((p = *ap) != NULL) {
73 if (equal(p, "-n")) {
74 nflag = 1;
75 ap++;
76 } else if (equal(p, "-e")) {
77 eflag = 1;
78 ap++;
79 }
80 }
81
82 while ((p = *ap++) != NULL) {
83 while ((c = *p++) != '\0') {
84 if (c == '\\' && eflag) {
85 switch (*p++) {
86 case 'a': c = '\a'; break; /* bell */
87 case 'b': c = '\b'; break;
88 case 'c': return 0; /* exit */
89 case 'e': c = 033; break; /* escape */
90 case 'f': c = '\f'; break;
91 case 'n': c = '\n'; break;
92 case 'r': c = '\r'; break;
93 case 't': c = '\t'; break;
94 case 'v': c = '\v'; break;
95 case '\\': break; /* c = '\\' */
96 case '0':
97 c = 0;
98 count = 3;
99 while (--count >= 0 && (unsigned)(*p - '0') < 8)
100 c = (c << 3) + (*p++ - '0');
101 break;
102 default:
103 /* Output the '/' and char following */
104 p--;
105 break;
106 }
107 }
108 putchar(c);
109 }
110 if (*ap)
111 putchar(' ');
112 }
113 if (! nflag)
114 putchar('\n');
115 return 0;
116 }
117