hush/libbb/bb_echo.c

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/* vi: set sw=4 ts=4: */
/*
* echo implementation for busybox
*
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*
* Original copyright notice is retained at the end of this file.
*/
/* BB_AUDIT SUSv3 compliant -- unless configured as fancy echo. */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/echo.html */
/* Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org)
*
* Because of behavioral differences, implemented configurable SUSv3
* or 'fancy' gnu-ish behaviors. Also, reduced size and fixed bugs.
* 1) In handling '\c' escape, the previous version only suppressed the
* trailing newline. SUSv3 specifies _no_ output after '\c'.
* 2) SUSv3 specifies that octal escapes are of the form \0{#{#{#}}}.
* The previous version version did not allow 4-digit octals.
*/
#include <stdio.h>
#include <string.h>
#include "busybox.h"
int bb_echo(int ATTRIBUTE_UNUSED argc, char **argv)
{
#ifndef CONFIG_FEATURE_FANCY_ECHO
#define eflag '\\'
++argv;
#else
const char *p;
int nflag = 1;
int eflag = 0;
while (*++argv && (**argv == '-')) {
/* If it appears that we are handling options, then make sure
* that all of the options specified are actually valid.
* Otherwise, the string should just be echoed.
*/
if (!*(p = *argv + 1)) { /* A single '-', so echo it. */
goto just_echo;
}
do {
if (strrchr("neE", *p) == 0) {
goto just_echo;
}
} while (*++p);
/* All of the options in this arg are valid, so handle them. */
p = *argv + 1;
do {
if (*p == 'n') {
nflag = 0;
} else if (*p == 'e') {
eflag = '\\';
} else {
eflag = 0;
}
} while (*++p);
}
just_echo:
#endif
while (*argv) {
register int c;
while ((c = *(*argv)++)) {
if (c == eflag) { /* Check for escape seq. */
if (**argv == 'c') {
/* '\c' means cancel newline and
* ignore all subsequent chars. */
return 0;
}
#ifndef CONFIG_FEATURE_FANCY_ECHO
/* SUSv3 specifies that octal escapes must begin with '0'. */
if (((unsigned int)(**argv - '1')) >= 7)
#endif
{
/* Since SUSv3 mandates a first digit of 0, 4-digit octals
* of the form \0### are accepted. */
if ((**argv == '0') && (((unsigned int)(argv[0][1] - '0')) < 8)) {
(*argv)++;
}
/* bb_process_escape_sequence can handle nul correctly */
c = bb_process_escape_sequence((const char **) argv);
}
}
putchar(c);
}
if (*++argv) {
putchar(' ');
}
}
#ifdef CONFIG_FEATURE_FANCY_ECHO
if (nflag) {
putchar('\n');
}
#else
putchar('\n');
#endif
return 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. <BSD Advertising Clause omitted per the July 22, 1999 licensing change
* ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change>
*
* 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
*/