NetBSD/bin/sh/bltin/echo.c

117 lines
3.5 KiB
C

/* $NetBSD: echo.c,v 1.11 2003/08/07 09:05:40 agc Exp $ */
/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Kenneth Almquist.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)echo.c 8.1 (Berkeley) 5/31/93
*/
/*
* Echo command.
*
* echo is steeped in tradition - several of them!
* netbsd has supported 'echo [-n | -e] args' in spite of -e not being
* documented anywhere.
* Posix requires that -n be supported, output from strings containing
* \ is implementation defined
* The Single Unix Spec requires that \ escapes be treated as if -e
* were set, but that -n not be treated as an option.
* (ksh supports 'echo [-eEn] args', but not -- so that it is actually
* impossible to actually output '-n')
*
* It is suggested that 'printf "%b" "string"' be used to get \ sequences
* expanded. printf is now a builtin of netbsd's sh and csh.
*/
#define main echocmd
#include "bltin.h"
int
main(int argc, char **argv)
{
register char **ap;
register char *p;
register char c;
int count;
int nflag = 0;
int eflag = 0;
ap = argv;
if (argc)
ap++;
if ((p = *ap) != NULL) {
if (equal(p, "-n")) {
nflag = 1;
ap++;
} else if (equal(p, "-e")) {
eflag = 1;
ap++;
}
}
while ((p = *ap++) != NULL) {
while ((c = *p++) != '\0') {
if (c == '\\' && eflag) {
switch (*p++) {
case 'a': c = '\a'; break; /* bell */
case 'b': c = '\b'; break;
case 'c': return 0; /* exit */
case 'e': c = 033; break; /* escape */
case 'f': c = '\f'; break;
case 'n': c = '\n'; break;
case 'r': c = '\r'; break;
case 't': c = '\t'; break;
case 'v': c = '\v'; break;
case '\\': break; /* c = '\\' */
case '0':
c = 0;
count = 3;
while (--count >= 0 && (unsigned)(*p - '0') < 8)
c = (c << 3) + (*p++ - '0');
break;
default:
/* Output the '/' and char following */
p--;
break;
}
}
putchar(c);
}
if (*ap)
putchar(' ');
}
if (! nflag)
putchar('\n');
return 0;
}