echo.c revision 1.2 
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 *	@(#)echo.c	5.2 (Berkeley) 3/13/91
37 *
38 *	$Id: echo.c,v 1.2 1993/03/22 08:04:00 cgd Exp $
39 */
40
41/*
42 * Echo command.
43 */
44
45#define main echocmd
46
47#include "bltin.h"
48
49/* #define eflag 1 */
50
51main(argc, argv)  char **argv; {
52	register char **ap;
53	register char *p;
54	register char c;
55	int count;
56	int nflag = 0;
57#ifndef eflag
58	int eflag = 0;
59#endif
60
61	ap = argv;
62	if (argc)
63		ap++;
64	if ((p = *ap) != NULL) {
65		if (equal(p, "-n")) {
66			nflag++;
67			ap++;
68		} else if (equal(p, "-e")) {
69#ifndef eflag
70			eflag++;
71#endif
72			ap++;
73		}
74	}
75	while ((p = *ap++) != NULL) {
76		while ((c = *p++) != '\0') {
77			if (c == '\\' && eflag) {
78				switch (*p++) {
79				case 'b':  c = '\b';  break;
80				case 'c':  return 0;		/* exit */
81				case 'f':  c = '\f';  break;
82				case 'n':  c = '\n';  break;
83				case 'r':  c = '\r';  break;
84				case 't':  c = '\t';  break;
85				case 'v':  c = '\v';  break;
86				case '\\':  break;		/* c = '\\' */
87				case '0':
88					c = 0;
89					count = 3;
90					while (--count >= 0 && (unsigned)(*p - '0') < 8)
91						c = (c << 3) + (*p++ - '0');
92					break;
93				default:
94					p--;
95					break;
96				}
97			}
98			putchar(c);
99		}
100		if (*ap)
101			putchar(' ');
102	}
103	if (! nflag)
104		putchar('\n');
105	return 0;
106}
107