diff options
Diffstat (limited to 'coreutils/echo.c')
| -rw-r--r-- | coreutils/echo.c | 303 |
1 files changed, 303 insertions, 0 deletions
diff --git a/coreutils/echo.c b/coreutils/echo.c new file mode 100644 index 0000000..decca09 --- /dev/null +++ b/coreutils/echo.c @@ -0,0 +1,303 @@ +/* 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 did not allow 4-digit octals. + */ + +#include "libbb.h" + +/* This is a NOFORK applet. Be very careful! */ + +/* NB: can be used by shell even if not enabled as applet */ + +int echo_main(int argc UNUSED_PARAM, char **argv) +{ + const char *arg; +#if !ENABLE_FEATURE_FANCY_ECHO + enum { + eflag = '\\', + nflag = 1, /* 1 -- print '\n' */ + }; + + /* We must check that stdout is not closed. + * 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. */ +// TODO: check fcntl() & O_ACCMODE == O_WRONLY or O_RDWR? + if (fcntl(1, F_GETFL) == -1) + return 1; /* match coreutils 6.10 (sans error msg to stderr) */ + //if (dup2(1, 1) != 1) - old way + // return 1; + + arg = *++argv; + if (!arg) + goto newline_ret; +#else + const char *p; + char nflag = 1; + char eflag = 0; + + /* We must check that stdout is not closed. */ + if (fcntl(1, F_GETFL) == -1) + return 1; + + 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 (!strrchr("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; + + if (!eflag) { + /* optimization for very common case */ + fputs(arg, stdout); + } else while ((c = *arg++)) { + if (c == eflag) { /* Check for escape seq. */ + if (*arg == 'c') { + /* '\c' means cancel newline and + * ignore all subsequent chars. */ + goto ret; + } +#if !ENABLE_FEATURE_FANCY_ECHO + /* SUSv3 specifies that octal escapes must begin with '0'. */ + if ( ((int)(unsigned char)(*arg) - '0') >= 8) /* '8' or bigger */ +#endif + { + /* Since SUSv3 mandates a first digit of 0, 4-digit octals + * of the form \0### are accepted. */ + if (*arg == '0') { + /* NB: don't turn "...\0" into "...\" */ + if (arg[1] && ((unsigned char)(arg[1]) - '0') < 8) { + arg++; + } + } + /* bb_process_escape_sequence handles NUL correctly + * ("...\" case). */ + c = bb_process_escape_sequence(&arg); + } + } + bb_putchar(c); + } + + arg = *++argv; + if (!arg) + break; + bb_putchar(' '); + } + + newline_ret: + if (nflag) { + bb_putchar('\n'); + } + ret: + return fflush(stdout); +} + +/*- + * 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 (!strrchr("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) { /* Check for escape seq. */ + 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; + } +#if !ENABLE_FEATURE_FANCY_ECHO + /* SUSv3 specifies that octal escapes must begin with '0'. */ + if ( (((unsigned char)*arg) - '1') >= 7) +#endif + { + /* 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 |