coreutils/echo.c - codeaurora/busybox - Gitiles

 /* 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 source tree.
  *
  * Original copyright notice is retained at the end of this file.
  */
 /* 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 did not allow 4-digit octals.
  */
 //config:config ECHO
 //config:	bool "echo (1.8 kb)"
 //config:	default y
 //config:	help
 //config:	echo prints a specified string to stdout.
 //config:
 //config:# this entry also appears in shell/Config.in, next to the echo builtin
 //config:config FEATURE_FANCY_ECHO
 //config:	bool "Enable -n and -e options"
 //config:	default y
 //config:	depends on ECHO || ASH_ECHO || HUSH_ECHO

 //applet:IF_ECHO(APPLET_NOFORK(echo, echo, BB_DIR_BIN, BB_SUID_DROP, echo))

 //kbuild:lib-$(CONFIG_ECHO) += echo.o

 //kbuild:lib-$(CONFIG_ASH_ECHO)  += echo.o
 //kbuild:lib-$(CONFIG_HUSH_ECHO) += echo.o

 /* BB_AUDIT SUSv3 compliant -- unless configured as fancy echo. */
 /* http://www.opengroup.org/onlinepubs/007904975/utilities/echo.html */

 //usage:#define echo_trivial_usage
 //usage:	IF_FEATURE_FANCY_ECHO("[-neE] ") "[ARG]..."
 //usage:#define echo_full_usage "\n\n"
 //usage:       "Print ARGs to stdout"
 //usage:	IF_FEATURE_FANCY_ECHO( "\n"
 //usage:     "\n	-n	No trailing newline"
 //usage:     "\n	-e	Interpret backslash escapes (\\t=tab etc)"
 //usage:     "\n	-E	Don't interpret backslash escapes (default)"
 //usage:	)
 //usage:
 //usage:#define echo_example_usage
 //usage:       "$ echo \"Erik is cool\"\n"
 //usage:       "Erik is cool\n"
 //usage:	IF_FEATURE_FANCY_ECHO("$ echo -e \"Erik\\nis\\ncool\"\n"
 //usage:       "Erik\n"
 //usage:       "is\n"
 //usage:       "cool\n"
 //usage:       "$ echo \"Erik\\nis\\ncool\"\n"
 //usage:       "Erik\\nis\\ncool\n")

 #include "libbb.h"

 /* This is a NOFORK applet. Be very careful! */

 /* NB: can be used by shell even if not enabled as applet */

 /*
  * NB2: we don't use stdio, we need better error handing.
  * Examples include writing into non-opened stdout and error on write.
  *
  * With stdio, output gets shoveled into stdout buffer, and even
  * fflush cannot clear it out. It seems that even if libc receives
  * EBADF on write attempts, it feels determined to output data no matter what.
  * If echo is called by shell, it will try writing again later, and possibly
  * will clobber future output. Not good.
  *
  * Solaris has fpurge which discards buffered input. glibc has __fpurge.
  * But this function is not standard.
  */

 int echo_main(int argc UNUSED_PARAM, char **argv)
 {
 	char **pp;
 	const char *arg;
 	char *out;
 	char *buffer;
 	unsigned buflen;
 	int err;
 #if !ENABLE_FEATURE_FANCY_ECHO
 	enum {
 		eflag = 0,  /* 0 -- disable escape sequences */
 		nflag = 1,  /* 1 -- print '\n' */
 	};

 	argv++;
 #else
 	char nflag = 1;
 	char eflag = 0;

 	while ((arg = *++argv) != NULL) {
 		char n, e;

 		if (arg[0] != '-')
 			break; /* not an option arg, echo it */

 		/* 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.
 		 */
 		arg++;
 		n = nflag;
 		e = eflag;
 		do {
 			if (*arg == 'n')
 				n = 0;
 			else if (*arg == 'e')
 				e = '\\';
 			else if (*arg != 'E') {
 				/* "-ccc" arg with one of c's invalid, echo it */
 				/* arg consisting from just "-" also handled here */
 				goto just_echo;
 			}
 		} while (*++arg);
 		nflag = n;
 		eflag = e;
 	}
  just_echo:
 #endif

 	buflen = 0;
 	pp = argv;
 	while ((arg = *pp) != NULL) {
 		buflen += strlen(arg) + 1;
 		pp++;
 	}
 	out = buffer = xmalloc(buflen + 1); /* +1 is needed for "no args" case */

 	while ((arg = *argv) != NULL) {
 		int c;

 		if (!eflag) {
 			/* optimization for very common case */
 			out = stpcpy(out, arg);
 		} else
 		while ((c = *arg++) != '\0') {
 			if (c == eflag) {
 				/* This is an "\x" sequence */

 				if (*arg == 'c') {
 					/* "\c" means cancel newline and
 					 * ignore all subsequent chars. */
 					goto do_write;
 				}
 				/* Since SUSv3 mandates a first digit of 0, 4-digit octals
 				* of the form \0### are accepted. */
 				if (*arg == '0') {
 					if ((unsigned char)(arg[1] - '0') < 8) {
 						/* 2nd char is 0..7: skip leading '0' */
 						arg++;
 					}
 				}
 				/* bb_process_escape_sequence handles NUL correctly
 				 * ("...\" case). */
 				{
 					/* optimization: don't force arg to be on-stack,
 					 * use another variable for that. ~30 bytes win */
 					const char *z = arg;
 					c = bb_process_escape_sequence(&z);
 					arg = z;
 				}
 			}
 			*out++ = c;
 		}

 		if (!*++argv)
 			break;
 		*out++ = ' ';
 	}

 	if (nflag) {
 		*out++ = '\n';
 	}

  do_write:
 	/* Careful to error out on partial writes too (think ENOSPC!) */
 	errno = 0;
 	err = full_write(STDOUT_FILENO, buffer, out - buffer) != out - buffer;
 	if (err) {
 		bb_simple_perror_msg(bb_msg_write_error);
 	}
 	free(buffer);
 	return err;
 }

 /*
  * 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
  */

 #ifdef VERSION_WITH_WRITEV
 /* We can't use stdio.
  * The reason for this is highly non-obvious.
  * echo_main is used from shell. Shell must correctly handle "echo foo"
  * if stdout is closed. With stdio, output gets shoveled into
  * stdout buffer, and even fflush cannot clear it out. It seems that
  * even if libc receives EBADF on write attempts, it feels determined
  * to output data no matter what. So it will try later,
  * and possibly will clobber future output. Not good.
  *
  * Using writev instead, with 'direct' conversion of argv vector.
  */

 int echo_main(int argc, char **argv)
 {
 	struct iovec io[argc];
 	struct iovec *cur_io = io;
 	char *arg;
 	char *p;
 #if !ENABLE_FEATURE_FANCY_ECHO
 	enum {
 		eflag = '\\',
 		nflag = 1,  /* 1 -- print '\n' */
 	};
 	arg = *++argv;
 	if (!arg)
 		goto newline_ret;
 #else
 	char nflag = 1;
 	char eflag = 0;

 	while (1) {
 		arg = *++argv;
 		if (!arg)
 			goto newline_ret;
 		if (*arg != '-')
 			break;

 		/* 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.
 		 */
 		p = arg + 1;
 		if (!*p)	/* A single '-', so echo it. */
 			goto just_echo;

 		do {
 			if (!strchr("neE", *p))
 				goto just_echo;
 		} while (*++p);

 		/* All of the options in this arg are valid, so handle them. */
 		p = arg + 1;
 		do {
 			if (*p == 'n')
 				nflag = 0;
 			if (*p == 'e')
 				eflag = '\\';
 		} while (*++p);
 	}
  just_echo:
 #endif

 	while (1) {
 		/* arg is already == *argv and isn't NULL */
 		int c;

 		cur_io->iov_base = p = arg;

 		if (!eflag) {
 			/* optimization for very common case */
 			p += strlen(arg);
 		} else while ((c = *arg++)) {
 			if (c == eflag) {
 				/* This is an "\x" sequence */

 				if (*arg == 'c') {
 					/* "\c" means cancel newline and
 					 * ignore all subsequent chars. */
 					cur_io->iov_len = p - (char*)cur_io->iov_base;
 					cur_io++;
 					goto ret;
 				}
 				/* Since SUSv3 mandates a first digit of 0, 4-digit octals
 				* of the form \0### are accepted. */
 				if (*arg == '0' && (unsigned char)(arg[1] - '0') < 8) {
 					arg++;
 				}
 //FIXME? we also accept non-0 starting sequences (see echo-prints-slash_41 test)
 // echo -ne '-\41-' prints "-!-". bash 5.0.17 does not (prints "-\41-").
 				/* bb_process_escape_sequence can handle nul correctly */
 				c = bb_process_escape_sequence( (void*) &arg);
 			}
 			*p++ = c;
 		}

 		arg = *++argv;
 		if (arg)
 			*p++ = ' ';
 		cur_io->iov_len = p - (char*)cur_io->iov_base;
 		cur_io++;
 		if (!arg)
 			break;
 	}

  newline_ret:
 	if (nflag) {
 		cur_io->iov_base = (char*)"\n";
 		cur_io->iov_len = 1;
 		cur_io++;
 	}
  ret:
 	/* TODO: implement and use full_writev? */
 	return writev(1, io, (cur_io - io)) >= 0;
 }
 #endif
	/* 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 source tree.
	*
	* Original copyright notice is retained at the end of this file.
	*/
	/* 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 did not allow 4-digit octals.
	*/
	//config:config ECHO
	//config: bool "echo (1.8 kb)"
	//config: default y
	//config: help
	//config: echo prints a specified string to stdout.
	//config:
	//config:# this entry also appears in shell/Config.in, next to the echo builtin
	//config:config FEATURE_FANCY_ECHO
	//config: bool "Enable -n and -e options"
	//config: default y
	//config: depends on ECHO \|\| ASH_ECHO \|\| HUSH_ECHO

	//applet:IF_ECHO(APPLET_NOFORK(echo, echo, BB_DIR_BIN, BB_SUID_DROP, echo))

	//kbuild:lib-$(CONFIG_ECHO) += echo.o

	//kbuild:lib-$(CONFIG_ASH_ECHO) += echo.o
	//kbuild:lib-$(CONFIG_HUSH_ECHO) += echo.o

	/* BB_AUDIT SUSv3 compliant -- unless configured as fancy echo. */
	/* http://www.opengroup.org/onlinepubs/007904975/utilities/echo.html */

	//usage:#define echo_trivial_usage
	//usage: IF_FEATURE_FANCY_ECHO("[-neE] ") "[ARG]..."
	//usage:#define echo_full_usage "\n\n"
	//usage: "Print ARGs to stdout"
	//usage: IF_FEATURE_FANCY_ECHO( "\n"
	//usage: "\n -n No trailing newline"
	//usage: "\n -e Interpret backslash escapes (\\t=tab etc)"
	//usage: "\n -E Don't interpret backslash escapes (default)"
	//usage: )
	//usage:
	//usage:#define echo_example_usage
	//usage: "$ echo \"Erik is cool\"\n"
	//usage: "Erik is cool\n"
	//usage: IF_FEATURE_FANCY_ECHO("$ echo -e \"Erik\\nis\\ncool\"\n"
	//usage: "Erik\n"
	//usage: "is\n"
	//usage: "cool\n"
	//usage: "$ echo \"Erik\\nis\\ncool\"\n"
	//usage: "Erik\\nis\\ncool\n")

	#include "libbb.h"

	/* This is a NOFORK applet. Be very careful! */

	/* NB: can be used by shell even if not enabled as applet */

	/*
	* NB2: we don't use stdio, we need better error handing.
	* Examples include writing into non-opened stdout and error on write.
	*
	* With stdio, output gets shoveled into stdout buffer, and even
	* fflush cannot clear it out. It seems that even if libc receives
	* EBADF on write attempts, it feels determined to output data no matter what.
	* If echo is called by shell, it will try writing again later, and possibly
	* will clobber future output. Not good.
	*
	* Solaris has fpurge which discards buffered input. glibc has __fpurge.
	* But this function is not standard.
	*/

	int echo_main(int argc UNUSED_PARAM, char **argv)
	{
	char **pp;
	const char *arg;
	char *out;
	char *buffer;
	unsigned buflen;
	int err;
	#if !ENABLE_FEATURE_FANCY_ECHO
	enum {
	eflag = 0, /* 0 -- disable escape sequences */
	nflag = 1, /* 1 -- print '\n' */
	};

	argv++;
	#else
	char nflag = 1;
	char eflag = 0;

	while ((arg = *++argv) != NULL) {
	char n, e;

	if (arg[0] != '-')
	break; /* not an option arg, echo it */

	/* 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.
	*/
	arg++;
	n = nflag;
	e = eflag;
	do {
	if (*arg == 'n')
	n = 0;
	else if (*arg == 'e')
	e = '\\';
	else if (*arg != 'E') {
	/* "-ccc" arg with one of c's invalid, echo it */
	/* arg consisting from just "-" also handled here */
	goto just_echo;
	}
	} while (*++arg);
	nflag = n;
	eflag = e;
	}
	just_echo:
	#endif

	buflen = 0;
	pp = argv;
	while ((arg = *pp) != NULL) {
	buflen += strlen(arg) + 1;
	pp++;
	}
	out = buffer = xmalloc(buflen + 1); /* +1 is needed for "no args" case */

	while ((arg = *argv) != NULL) {
	int c;

	if (!eflag) {
	/* optimization for very common case */
	out = stpcpy(out, arg);
	} else
	while ((c = *arg++) != '\0') {
	if (c == eflag) {
	/* This is an "\x" sequence */

	if (*arg == 'c') {
	/* "\c" means cancel newline and
	* ignore all subsequent chars. */
	goto do_write;
	}
	/* Since SUSv3 mandates a first digit of 0, 4-digit octals
	* of the form \0### are accepted. */
	if (*arg == '0') {
	if ((unsigned char)(arg[1] - '0') < 8) {
	/* 2nd char is 0..7: skip leading '0' */
	arg++;
	}
	}
	/* bb_process_escape_sequence handles NUL correctly
	* ("...\" case). */
	{
	/* optimization: don't force arg to be on-stack,
	* use another variable for that. ~30 bytes win */
	const char *z = arg;
	c = bb_process_escape_sequence(&z);
	arg = z;
	}
	}
	*out++ = c;
	}

	if (!*++argv)
	break;
	*out++ = ' ';
	}

	if (nflag) {
	*out++ = '\n';
	}

	do_write:
	/* Careful to error out on partial writes too (think ENOSPC!) */
	errno = 0;
	err = full_write(STDOUT_FILENO, buffer, out - buffer) != out - buffer;
	if (err) {
	bb_simple_perror_msg(bb_msg_write_error);
	}
	free(buffer);
	return err;
	}

	/*
	* 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
	*/

	#ifdef VERSION_WITH_WRITEV
	/* We can't use stdio.
	* The reason for this is highly non-obvious.
	* echo_main is used from shell. Shell must correctly handle "echo foo"
	* if stdout is closed. With stdio, output gets shoveled into
	* stdout buffer, and even fflush cannot clear it out. It seems that
	* even if libc receives EBADF on write attempts, it feels determined
	* to output data no matter what. So it will try later,
	* and possibly will clobber future output. Not good.
	*
	* Using writev instead, with 'direct' conversion of argv vector.
	*/

	int echo_main(int argc, char **argv)
	{
	struct iovec io[argc];
	struct iovec *cur_io = io;
	char *arg;
	char *p;
	#if !ENABLE_FEATURE_FANCY_ECHO
	enum {
	eflag = '\\',
	nflag = 1, /* 1 -- print '\n' */
	};
	arg = *++argv;
	if (!arg)
	goto newline_ret;
	#else
	char nflag = 1;
	char eflag = 0;

	while (1) {
	arg = *++argv;
	if (!arg)
	goto newline_ret;
	if (*arg != '-')
	break;

	/* 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.
	*/
	p = arg + 1;
	if (!p) / A single '-', so echo it. */
	goto just_echo;

	do {
	if (!strchr("neE", *p))
	goto just_echo;
	} while (*++p);

	/* All of the options in this arg are valid, so handle them. */
	p = arg + 1;
	do {
	if (*p == 'n')
	nflag = 0;
	if (*p == 'e')
	eflag = '\\';
	} while (*++p);
	}
	just_echo:
	#endif

	while (1) {
	/* arg is already == argv and isn't NULL /
	int c;

	cur_io->iov_base = p = arg;

	if (!eflag) {
	/* optimization for very common case */
	p += strlen(arg);
	} else while ((c = *arg++)) {
	if (c == eflag) {
	/* This is an "\x" sequence */

	if (*arg == 'c') {
	/* "\c" means cancel newline and
	* ignore all subsequent chars. */
	cur_io->iov_len = p - (char*)cur_io->iov_base;
	cur_io++;
	goto ret;
	}
	/* Since SUSv3 mandates a first digit of 0, 4-digit octals
	* of the form \0### are accepted. */
	if (*arg == '0' && (unsigned char)(arg[1] - '0') < 8) {
	arg++;
	}
	//FIXME? we also accept non-0 starting sequences (see echo-prints-slash_41 test)
	// echo -ne '-\41-' prints "-!-". bash 5.0.17 does not (prints "-\41-").
	/* bb_process_escape_sequence can handle nul correctly */
	c = bb_process_escape_sequence( (void*) &arg);
	}
	*p++ = c;
	}

	arg = *++argv;
	if (arg)
	*p++ = ' ';
	cur_io->iov_len = p - (char*)cur_io->iov_base;
	cur_io++;
	if (!arg)
	break;
	}

	newline_ret:
	if (nflag) {
	cur_io->iov_base = (char*)"\n";
	cur_io->iov_len = 1;
	cur_io++;
	}
	ret:
	/* TODO: implement and use full_writev? */
	return writev(1, io, (cur_io - io)) >= 0;
	}
	#endif