xref: /freebsd/bin/sh/bltin/echo.c (revision bdd1243df58e60e85101c09001d9812a789b6bc4)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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	8.2 (Berkeley) 5/4/95
35  */
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 /*
41  * Echo command.
42  */
43 
44 #define main echocmd
45 
46 #include "bltin.h"
47 
48 /* #define eflag 1 */
49 
50 int
51 main(int argc, char *argv[])
52 {
53 	char **ap;
54 	char *p;
55 	char c;
56 	int count;
57 	int nflag = 0;
58 #ifndef eflag
59 	int eflag = 0;
60 #endif
61 
62 	ap = argv;
63 	if (argc)
64 		ap++;
65 	if ((p = *ap) != NULL) {
66 		if (equal(p, "-n")) {
67 			nflag++;
68 			ap++;
69 		} else if (equal(p, "-e")) {
70 #ifndef eflag
71 			eflag++;
72 #endif
73 			ap++;
74 		}
75 	}
76 	while ((p = *ap++) != NULL) {
77 		while ((c = *p++) != '\0') {
78 			if (c == '\\' && eflag) {
79 				switch (*p++) {
80 				case 'a':  c = '\a';  break;
81 				case 'b':  c = '\b';  break;
82 				case 'c':  return 0;		/* exit */
83 				case 'e':  c = '\033';  break;
84 				case 'f':  c = '\f';  break;
85 				case 'n':  c = '\n';  break;
86 				case 'r':  c = '\r';  break;
87 				case 't':  c = '\t';  break;
88 				case 'v':  c = '\v';  break;
89 				case '\\':  break;		/* c = '\\' */
90 				case '0':
91 					c = 0;
92 					count = 3;
93 					while (--count >= 0 && (unsigned)(*p - '0') < 8)
94 						c = (c << 3) + (*p++ - '0');
95 					break;
96 				default:
97 					p--;
98 					break;
99 				}
100 			}
101 			putchar(c);
102 		}
103 		if (*ap)
104 			putchar(' ');
105 	}
106 	if (! nflag)
107 		putchar('\n');
108 	return 0;
109 }
110