hush/echo.c
Erik Andersen 9cf3bfa7c1 More doc updates for BusyBox, with fixes to apps for bugs revealed
while trying to write docs . :-)
 -Erik
2000-04-13 18:49:43 +00:00

138 lines
4.4 KiB
C

/* vi: set sw=4 ts=4: */
/*
* echo implementation for busybox
*
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Original copyright notice is retained at the end of this file.
*/
#include "internal.h"
#include <stdio.h>
static const char uname_usage[] =
"echo [-neE] [ARG ...]\n\n"
"Prints the specified ARGs to stdout\n\n"
"Options:\n"
"\t-n\tsuppress trailing newline\n"
"\t-e\tinterpret backslash-escaped characters (i.e. \\t=tab etc)\n"
"\t-E\tdisable interpretation of backslash-escaped characters\n";
extern int
echo_main(int argc, char** argv)
{
register char **ap;
register char *p;
register char c;
int nflag = 0;
int eflag = 0;
ap = argv;
if (argc)
ap++;
while ((p = *ap) != NULL && *p == '-') {
if (strcmp(p, "-n")==0) {
nflag = 1;
} else if (strcmp(p, "-e")==0) {
eflag = 1;
} else if (strcmp(p, "-E")==0) {
eflag = 0;
}
else if (strncmp(p, "--", 2)==0) {
usage( uname_usage);
}
else break;
ap++;
}
while ((p = *ap++) != NULL) {
while ((c = *p++) != '\0') {
if (c == '\\' && eflag) {
switch (c = *p++) {
case 'a': c = '\007'; break;
case 'b': c = '\b'; break;
case 'c': exit( 0); /* exit */
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': case '1': case '2': case '3':
case '4': case '5': case '6': case '7':
c -= '0';
if (*p >= '0' && *p <= '7')
c = c * 8 + (*p++ - '0');
if (*p >= '0' && *p <= '7')
c = c * 8 + (*p++ - '0');
break;
default:
p--;
break;
}
}
putchar(c);
}
if (*ap)
putchar(' ');
}
if (! nflag)
putchar('\n');
fflush(stdout);
exit( 0);
}
/*-
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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
*/