echo.c revision 1.6 
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 *	from: @(#)echo.c	8.1 (Berkeley) 5/31/93
37 *	$Id: echo.c,v 1.6 1994/06/11 16:12:44 mycroft Exp $
38 */
39
40/*
41 * Echo command.
42 */
43
44#define main echocmd
45
46#include "bltin.h"
47
48/* #define eflag 1 */
49
50main(argc, argv)  char **argv; {
51	register char **ap;
52	register char *p;
53	register char c;
54	int count;
55	int nflag = 0;
56#ifndef eflag
57	int eflag = 0;
58#endif
59
60	ap = argv;
61	if (argc)
62		ap++;
63	if ((p = *ap) != NULL) {
64		if (equal(p, "-n")) {
65			nflag++;
66			ap++;
67		} else if (equal(p, "-e")) {
68#ifndef eflag
69			eflag++;
70#endif
71			ap++;
72		}
73	}
74	while ((p = *ap++) != NULL) {
75		while ((c = *p++) != '\0') {
76			if (c == '\\' && eflag) {
77				switch (*p++) {
78				case 'b':  c = '\b';  break;
79				case 'c':  return 0;		/* exit */
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