echo.c revision 1.5 
1/*-
2 * Copyright (c) 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kenneth Almquist.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 *	@(#)echo.c	8.1 (Berkeley) 5/31/93
37 */
38
39/*
40 * Echo command.
41 */
42
43#define main echocmd
44
45#include "bltin.h"
46
47/* #define eflag 1 */
48
49main(argc, argv)  char **argv; {
50	register char **ap;
51	register char *p;
52	register char c;
53	int count;
54	int nflag = 0;
55#ifndef eflag
56	int eflag = 0;
57#endif
58
59	ap = argv;
60	if (argc)
61		ap++;
62	if ((p = *ap) != NULL) {
63		if (equal(p, "-n")) {
64			nflag++;
65			ap++;
66		} else if (equal(p, "-e")) {
67#ifndef eflag
68			eflag++;
69#endif
70			ap++;
71		}
72	}
73	while ((p = *ap++) != NULL) {
74		while ((c = *p++) != '\0') {
75			if (c == '\\' && eflag) {
76				switch (*p++) {
77				case 'b':  c = '\b';  break;
78				case 'c':  return 0;		/* exit */
79				case 'f':  c = '\f';  break;
80				case 'n':  c = '\n';  break;
81				case 'r':  c = '\r';  break;
82				case 't':  c = '\t';  break;
83				case 'v':  c = '\v';  break;
84				case '\\':  break;		/* c = '\\' */
85				case '0':
86					c = 0;
87					count = 3;
88					while (--count >= 0 && (unsigned)(*p - '0') < 8)
89						c = (c << 3) + (*p++ - '0');
90					break;
91				default:
92					p--;
93					break;
94				}
95			}
96			putchar(c);
97		}
98		if (*ap)
99			putchar(' ');
100	}
101	if (! nflag)
102		putchar('\n');
103	return 0;
104}
105