xref: /freebsd/bin/sh/bltin/echo.c (revision bdcbfde31e8e9b343f113a1956384bdf30d1ed62)
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 
35 #include <sys/cdefs.h>
36 /*
37  * Echo command.
38  */
39 
40 #define main echocmd
41 
42 #include "bltin.h"
43 
44 /* #define eflag 1 */
45 
46 int
47 main(int argc, char *argv[])
48 {
49 	char **ap;
50 	char *p;
51 	char c;
52 	int count;
53 	int nflag = 0;
54 #ifndef eflag
55 	int eflag = 0;
56 #endif
57 
58 	ap = argv;
59 	if (argc)
60 		ap++;
61 	if ((p = *ap) != NULL) {
62 		if (equal(p, "-n")) {
63 			nflag++;
64 			ap++;
65 		} else if (equal(p, "-e")) {
66 #ifndef eflag
67 			eflag++;
68 #endif
69 			ap++;
70 		}
71 	}
72 	while ((p = *ap++) != NULL) {
73 		while ((c = *p++) != '\0') {
74 			if (c == '\\' && eflag) {
75 				switch (*p++) {
76 				case 'a':  c = '\a';  break;
77 				case 'b':  c = '\b';  break;
78 				case 'c':  return 0;		/* exit */
79 				case 'e':  c = '\033';  break;
80 				case 'f':  c = '\f';  break;
81 				case 'n':  c = '\n';  break;
82 				case 'r':  c = '\r';  break;
83 				case 't':  c = '\t';  break;
84 				case 'v':  c = '\v';  break;
85 				case '\\':  break;		/* c = '\\' */
86 				case '0':
87 					c = 0;
88 					count = 3;
89 					while (--count >= 0 && (unsigned)(*p - '0') < 8)
90 						c = (c << 3) + (*p++ - '0');
91 					break;
92 				default:
93 					p--;
94 					break;
95 				}
96 			}
97 			putchar(c);
98 		}
99 		if (*ap)
100 			putchar(' ');
101 	}
102 	if (! nflag)
103 		putchar('\n');
104 	return 0;
105 }
106