echo.c revision 1.4 
1/*-
2 * Copyright (c) 1991 The Regents of the University of California.
3 * 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
37#ifndef lint
38/*static char sccsid[] = "from: @(#)echo.c	5.2 (Berkeley) 3/13/91";*/
39static char rcsid[] = "$Id: echo.c,v 1.4 1993/08/01 18:58:43 mycroft Exp $";
40#endif /* not lint */
41
42/*
43 * Echo command.
44 */
45
46#define main echocmd
47
48#include "bltin.h"
49
50/* #define eflag 1 */
51
52main(argc, argv)  char **argv; {
53	register char **ap;
54	register char *p;
55	register 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 'b':  c = '\b';  break;
81				case 'c':  return 0;		/* exit */
82				case 'f':  c = '\f';  break;
83				case 'n':  c = '\n';  break;
84				case 'r':  c = '\r';  break;
85				case 't':  c = '\t';  break;
86				case 'v':  c = '\v';  break;
87				case '\\':  break;		/* c = '\\' */
88				case '0':
89					c = 0;
90					count = 3;
91					while (--count >= 0 && (unsigned)(*p - '0') < 8)
92						c = (c << 3) + (*p++ - '0');
93					break;
94				default:
95					p--;
96					break;
97				}
98			}
99			putchar(c);
100		}
101		if (*ap)
102			putchar(' ');
103	}
104	if (! nflag)
105		putchar('\n');
106	return 0;
107}
108