* 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.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*
* 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
* 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.
+ * 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-$(CONFIG_HUSH_ECHO) += echo.o
+
+/* BB_AUDIT SUSv3 compliant -- unless configured as fancy echo. */
+/* http://www.opengroup.org/onlinepubs/007904975/utilities/echo.html */
+
+//usage:#define echo_trivial_usage
+//usage: IF_FEATURE_FANCY_ECHO("[-neE] ") "[ARG]..."
+//usage:#define echo_full_usage "\n\n"
+//usage: "Print the specified ARGs to stdout"
+//usage: IF_FEATURE_FANCY_ECHO( "\n"
+//usage: "\n -n Suppress trailing newline"
+//usage: "\n -e Interpret backslash escapes (i.e., \\t=tab)"
+//usage: "\n -E Don't interpret backslash escapes (default)"
+//usage: )
+//usage:
+//usage:#define echo_example_usage
+//usage: "$ 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! */
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-#include "busybox.h"
+/* NB: can be used by shell even if not enabled as applet */
-int bb_echo(char **argv)
+/*
+ * 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)
{
-#ifndef CONFIG_FEATURE_FANCY_ECHO
-#define eflag '\\'
- ++argv;
+ char **pp;
+ const char *arg;
+ char *out;
+ char *buffer;
+ unsigned buflen;
+#if !ENABLE_FEATURE_FANCY_ECHO
+ enum {
+ eflag = 0, /* 0 -- disable escape sequences */
+ nflag = 1, /* 1 -- print '\n' */
+ };
+
+ argv++;
#else
- const char *p;
- int nflag = 1;
- int eflag = 0;
+ char nflag = 1;
+ char eflag = 0;
+
+ while ((arg = *++argv) != NULL) {
+ char n, e;
+
+ if (arg[0] != '-')
+ break; /* not an option arg, echo it */
- 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;
- }
-
+ arg++;
+ n = nflag;
+ e = eflag;
do {
- if (strrchr("neE", *p) == 0) {
+ 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 (*++p);
+ } while (*++arg);
+ nflag = n;
+ eflag = e;
+ }
+ just_echo:
+#endif
- /* 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);
+ 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 */
-just_echo:
-#endif
- while (*argv) {
+ while ((arg = *argv) != NULL) {
int c;
- while ((c = *(*argv)++)) {
- if (c == eflag) { /* Check for escape seq. */
- if (**argv == 'c') {
- /* '\c' means cancel newline and
+ 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. */
- return 0;
+ goto do_write;
}
-#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)++;
+ /* 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 can handle nul correctly */
- c = bb_process_escape_sequence((const char **) argv);
+ }
+ /* 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;
}
}
- putchar(c);
+ *out++ = c;
}
- if (*++argv) {
- putchar(' ');
- }
+ if (!*++argv)
+ break;
+ *out++ = ' ';
}
-#ifdef CONFIG_FEATURE_FANCY_ECHO
if (nflag) {
- putchar('\n');
+ *out++ = '\n';
}
-#else
- putchar('\n');
-#endif
- return 0;
-}
-int echo_main(int argc, char** argv);
-int echo_main(int argc, char** argv)
-{
- (void)bb_echo(argv);
- fflush_stdout_and_exit(EXIT_SUCCESS);
+ do_write:
+ /* Careful to error out on partial writes too (think ENOSPC!) */
+ errno = 0;
+ /*r =*/ full_write(STDOUT_FILENO, buffer, out - buffer);
+ free(buffer);
+ if (/*WRONG:r < 0*/ errno) {
+ bb_perror_msg(bb_msg_write_error);
+ return 1;
+ }
+ return 0;
}
-/*-
+/*
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* 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
+ * 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
*
* @(#)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++;
+ }
+ /* 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
projects / oweals / busybox.git / blobdiff