1 /* $NetBSD: echo.c,v 1.9 2002/11/24 22:35:44 christos Exp $ */ 2 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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)echo.c 8.1 (Berkeley) 5/31/93 39 */ 40 41 /* 42 * Echo command. 43 * 44 * echo is steeped in tradition - several of them! 45 * netbsd has supported 'echo [-n | -e] args' in spite of -e not being 46 * documented anywhere. 47 * Posix requires that -n be supported, output from strings containing 48 * \ is implementation defined 49 * The Single Unix Spec requires that \ escapes be treated as if -e 50 * were set, but that -n not be treated as an option. 51 * (ksh supports 'echo [-eEn] args', but not -- so that it is actually 52 * impossible to actually ouput '-n') 53 * 54 * It is suggested that 'printf "%b" "string"' be used to get \ sequences 55 * expanded. printf is now a builtin of netbsd's sh and csh. 56 */ 57 58 #define main echocmd 59 60 #include "bltin.h" 61 62 int 63 main(int argc, char **argv) 64 { 65 register char **ap; 66 register char *p; 67 register char c; 68 int count; 69 int nflag = 0; 70 int eflag = 0; 71 72 ap = argv; 73 if (argc) 74 ap++; 75 76 if ((p = *ap) != NULL) { 77 if (equal(p, "-n")) { 78 nflag = 1; 79 ap++; 80 } else if (equal(p, "-e")) { 81 eflag = 1; 82 ap++; 83 } 84 } 85 86 while ((p = *ap++) != NULL) { 87 while ((c = *p++) != '\0') { 88 if (c == '\\' && eflag) { 89 switch (*p++) { 90 case 'a': c = '\a'; break; /* bell */ 91 case 'b': c = '\b'; break; 92 case 'c': return 0; /* exit */ 93 case 'e': c = 033; break; /* escape */ 94 case 'f': c = '\f'; break; 95 case 'n': c = '\n'; break; 96 case 'r': c = '\r'; break; 97 case 't': c = '\t'; break; 98 case 'v': c = '\v'; break; 99 case '\\': break; /* c = '\\' */ 100 case '0': 101 c = 0; 102 count = 3; 103 while (--count >= 0 && (unsigned)(*p - '0') < 8) 104 c = (c << 3) + (*p++ - '0'); 105 break; 106 default: 107 /* Output the '/' and char following */ 108 p--; 109 break; 110 } 111 } 112 putchar(c); 113 } 114 if (*ap) 115 putchar(' '); 116 } 117 if (! nflag) 118 putchar('\n'); 119 return 0; 120 } 121