mirror of
https://github.com/sheumann/hush.git
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This change retains "or later" state! No licensing _changes_ here, only form is adjusted (article, space between "GPL" and "v2" and so on). Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
560 lines
14 KiB
C
560 lines
14 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* Mini xargs implementation for busybox
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*
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* (C) 2002,2003 by Vladimir Oleynik <dzo@simtreas.ru>
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*
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* Special thanks
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* - Mark Whitley and Glenn McGrath for stimulus to rewrite :)
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* - Mike Rendell <michael@cs.mun.ca>
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* and David MacKenzie <djm@gnu.ai.mit.edu>.
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*
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* Licensed under GPLv2 or later, see file LICENSE in this source tree.
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*
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* xargs is described in the Single Unix Specification v3 at
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* http://www.opengroup.org/onlinepubs/007904975/utilities/xargs.html
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*/
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//applet:IF_XARGS(APPLET_NOEXEC(xargs, xargs, _BB_DIR_USR_BIN, _BB_SUID_DROP, xargs))
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//kbuild:lib-$(CONFIG_XARGS) += xargs.o
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//config:config XARGS
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//config: bool "xargs"
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//config: default y
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//config: help
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//config: xargs is used to execute a specified command for
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//config: every item from standard input.
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//config:
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//config:config FEATURE_XARGS_SUPPORT_CONFIRMATION
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//config: bool "Enable -p: prompt and confirmation"
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//config: default y
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//config: depends on XARGS
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//config: help
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//config: Support -p: prompt the user whether to run each command
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//config: line and read a line from the terminal.
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//config:
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//config:config FEATURE_XARGS_SUPPORT_QUOTES
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//config: bool "Enable single and double quotes and backslash"
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//config: default y
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//config: depends on XARGS
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//config: help
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//config: Support quoting in the input.
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//config:
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//config:config FEATURE_XARGS_SUPPORT_TERMOPT
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//config: bool "Enable -x: exit if -s or -n is exceeded"
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//config: default y
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//config: depends on XARGS
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//config: help
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//config: Support -x: exit if the command size (see the -s or -n option)
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//config: is exceeded.
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//config:
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//config:config FEATURE_XARGS_SUPPORT_ZERO_TERM
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//config: bool "Enable -0: NUL-terminated input"
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//config: default y
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//config: depends on XARGS
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//config: help
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//config: Support -0: input items are terminated by a NUL character
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//config: instead of whitespace, and the quotes and backslash
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//config: are not special.
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#include "libbb.h"
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/* This is a NOEXEC applet. Be very careful! */
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//#define dbg_msg(...) bb_error_msg(__VA_ARGS__)
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#define dbg_msg(...) ((void)0)
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#ifdef TEST
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# ifndef ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION
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# define ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION 1
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# endif
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# ifndef ENABLE_FEATURE_XARGS_SUPPORT_QUOTES
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# define ENABLE_FEATURE_XARGS_SUPPORT_QUOTES 1
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# endif
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# ifndef ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT
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# define ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT 1
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# endif
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# ifndef ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
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# define ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM 1
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# endif
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#endif
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struct globals {
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char **args;
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const char *eof_str;
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int idx;
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} FIX_ALIASING;
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#define G (*(struct globals*)&bb_common_bufsiz1)
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#define INIT_G() do { } while (0)
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/*
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* This function has special algorithm.
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* Don't use fork and include to main!
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*/
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static int xargs_exec(void)
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{
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int status;
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status = spawn_and_wait(G.args);
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if (status < 0) {
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bb_simple_perror_msg(G.args[0]);
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return errno == ENOENT ? 127 : 126;
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}
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if (status == 255) {
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bb_error_msg("%s: exited with status 255; aborting", G.args[0]);
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return 124;
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}
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if (status >= 0x180) {
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bb_error_msg("%s: terminated by signal %d",
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G.args[0], status - 0x180);
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return 125;
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}
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if (status)
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return 123;
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return 0;
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}
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/* In POSIX/C locale isspace is only these chars: "\t\n\v\f\r" and space.
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* "\t\n\v\f\r" happen to have ASCII codes 9,10,11,12,13.
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*/
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#define ISSPACE(a) ({ unsigned char xargs__isspace = (a) - 9; xargs__isspace == (' ' - 9) || xargs__isspace <= (13 - 9); })
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static void store_param(char *s)
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{
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/* Grow by 256 elements at once */
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if (!(G.idx & 0xff)) { /* G.idx == N*256 */
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/* Enlarge, make G.args[(N+1)*256 - 1] last valid idx */
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G.args = xrealloc(G.args, sizeof(G.args[0]) * (G.idx + 0x100));
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}
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G.args[G.idx++] = s;
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}
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/* process[0]_stdin:
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* Read characters into buf[n_max_chars+1], and when parameter delimiter
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* is seen, store the address of a new parameter to args[].
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* If reading discovers that last chars do not form the complete
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* parameter, the pointer to the first such "tail character" is returned.
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* (buf has extra byte at the end to accomodate terminating NUL
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* of "tail characters" string).
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* Otherwise, the returned pointer points to NUL byte.
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* On entry, buf[] may contain some "seed chars" which are to become
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* the beginning of the first parameter.
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*/
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#if ENABLE_FEATURE_XARGS_SUPPORT_QUOTES
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static char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf)
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{
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#define NORM 0
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#define QUOTE 1
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#define BACKSLASH 2
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#define SPACE 4
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char q = '\0'; /* quote char */
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char state = NORM;
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char *s = buf; /* start of the word */
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char *p = s + strlen(buf); /* end of the word */
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buf += n_max_chars; /* past buffer's end */
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/* "goto ret" is used instead of "break" to make control flow
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* more obvious: */
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while (1) {
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int c = getchar();
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if (c == EOF) {
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if (p != s)
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goto close_word;
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goto ret;
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}
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if (state == BACKSLASH) {
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state = NORM;
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goto set;
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}
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if (state == QUOTE) {
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if (c != q)
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goto set;
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q = '\0';
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state = NORM;
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} else { /* if (state == NORM) */
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if (ISSPACE(c)) {
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if (p != s) {
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close_word:
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state = SPACE;
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c = '\0';
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goto set;
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}
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} else {
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if (c == '\\') {
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state = BACKSLASH;
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} else if (c == '\'' || c == '"') {
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q = c;
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state = QUOTE;
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} else {
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set:
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*p++ = c;
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}
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}
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}
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if (state == SPACE) { /* word's delimiter or EOF detected */
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if (q) {
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bb_error_msg_and_die("unmatched %s quote",
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q == '\'' ? "single" : "double");
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}
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/* A full word is loaded */
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if (G.eof_str) {
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if (strcmp(s, G.eof_str) == 0) {
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while (getchar() != EOF)
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continue;
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p = s;
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goto ret;
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}
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}
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store_param(s);
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dbg_msg("args[]:'%s'", s);
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s = p;
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n_max_arg--;
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if (n_max_arg == 0) {
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goto ret;
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}
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state = NORM;
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}
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if (p == buf) {
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goto ret;
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}
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}
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ret:
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*p = '\0';
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/* store_param(NULL) - caller will do it */
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dbg_msg("return:'%s'", s);
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return s;
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}
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#else
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/* The variant does not support single quotes, double quotes or backslash */
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static char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf)
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{
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char *s = buf; /* start of the word */
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char *p = s + strlen(buf); /* end of the word */
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buf += n_max_chars; /* past buffer's end */
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while (1) {
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int c = getchar();
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if (c == EOF) {
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if (p == s)
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goto ret;
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}
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if (c == EOF || ISSPACE(c)) {
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if (p == s)
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continue;
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c = EOF;
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}
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*p++ = (c == EOF ? '\0' : c);
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if (c == EOF) { /* word's delimiter or EOF detected */
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/* A full word is loaded */
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if (G.eof_str) {
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if (strcmp(s, G.eof_str) == 0) {
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while (getchar() != EOF)
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continue;
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p = s;
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goto ret;
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}
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}
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store_param(s);
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dbg_msg("args[]:'%s'", s);
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s = p;
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n_max_arg--;
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if (n_max_arg == 0) {
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goto ret;
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}
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}
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if (p == buf) {
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goto ret;
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}
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}
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ret:
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*p = '\0';
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/* store_param(NULL) - caller will do it */
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dbg_msg("return:'%s'", s);
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return s;
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}
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#endif /* FEATURE_XARGS_SUPPORT_QUOTES */
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#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
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static char* FAST_FUNC process0_stdin(int n_max_chars, int n_max_arg, char *buf)
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{
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char *s = buf; /* start of the word */
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char *p = s + strlen(buf); /* end of the word */
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buf += n_max_chars; /* past buffer's end */
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while (1) {
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int c = getchar();
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if (c == EOF) {
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if (p == s)
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goto ret;
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c = '\0';
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}
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*p++ = c;
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if (c == '\0') { /* word's delimiter or EOF detected */
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/* A full word is loaded */
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store_param(s);
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dbg_msg("args[]:'%s'", s);
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s = p;
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n_max_arg--;
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if (n_max_arg == 0) {
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goto ret;
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}
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}
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if (p == buf) {
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goto ret;
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}
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}
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ret:
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*p = '\0';
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/* store_param(NULL) - caller will do it */
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dbg_msg("return:'%s'", s);
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return s;
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}
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#endif /* FEATURE_XARGS_SUPPORT_ZERO_TERM */
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#if ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION
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/* Prompt the user for a response, and
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if the user responds affirmatively, return true;
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otherwise, return false. Uses "/dev/tty", not stdin. */
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static int xargs_ask_confirmation(void)
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{
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FILE *tty_stream;
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int c, savec;
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tty_stream = xfopen_for_read(CURRENT_TTY);
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fputs(" ?...", stderr);
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fflush_all();
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c = savec = getc(tty_stream);
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while (c != EOF && c != '\n')
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c = getc(tty_stream);
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fclose(tty_stream);
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return (savec == 'y' || savec == 'Y');
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}
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#else
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# define xargs_ask_confirmation() 1
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#endif
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//usage:#define xargs_trivial_usage
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//usage: "[OPTIONS] [PROG ARGS]"
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//usage:#define xargs_full_usage "\n\n"
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//usage: "Run PROG on every item given by stdin\n"
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//usage: "\nOptions:"
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//usage: IF_FEATURE_XARGS_SUPPORT_CONFIRMATION(
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//usage: "\n -p Ask user whether to run each command"
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//usage: )
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//usage: "\n -r Don't run command if input is empty"
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//usage: IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(
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//usage: "\n -0 Input is separated by NUL characters"
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//usage: )
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//usage: "\n -t Print the command on stderr before execution"
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//usage: "\n -e[STR] STR stops input processing"
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//usage: "\n -n N Pass no more than N args to PROG"
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//usage: "\n -s N Pass command line of no more than N bytes"
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//usage: IF_FEATURE_XARGS_SUPPORT_TERMOPT(
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//usage: "\n -x Exit if size is exceeded"
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//usage: )
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//usage:#define xargs_example_usage
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//usage: "$ ls | xargs gzip\n"
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//usage: "$ find . -name '*.c' -print | xargs rm\n"
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/* Correct regardless of combination of CONFIG_xxx */
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enum {
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OPTBIT_VERBOSE = 0,
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OPTBIT_NO_EMPTY,
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OPTBIT_UPTO_NUMBER,
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OPTBIT_UPTO_SIZE,
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OPTBIT_EOF_STRING,
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OPTBIT_EOF_STRING1,
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IF_FEATURE_XARGS_SUPPORT_CONFIRMATION(OPTBIT_INTERACTIVE,)
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IF_FEATURE_XARGS_SUPPORT_TERMOPT( OPTBIT_TERMINATE ,)
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IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( OPTBIT_ZEROTERM ,)
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OPT_VERBOSE = 1 << OPTBIT_VERBOSE ,
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OPT_NO_EMPTY = 1 << OPTBIT_NO_EMPTY ,
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OPT_UPTO_NUMBER = 1 << OPTBIT_UPTO_NUMBER,
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OPT_UPTO_SIZE = 1 << OPTBIT_UPTO_SIZE ,
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OPT_EOF_STRING = 1 << OPTBIT_EOF_STRING , /* GNU: -e[<param>] */
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OPT_EOF_STRING1 = 1 << OPTBIT_EOF_STRING1, /* SUS: -E<param> */
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OPT_INTERACTIVE = IF_FEATURE_XARGS_SUPPORT_CONFIRMATION((1 << OPTBIT_INTERACTIVE)) + 0,
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OPT_TERMINATE = IF_FEATURE_XARGS_SUPPORT_TERMOPT( (1 << OPTBIT_TERMINATE )) + 0,
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OPT_ZEROTERM = IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( (1 << OPTBIT_ZEROTERM )) + 0,
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};
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#define OPTION_STR "+trn:s:e::E:" \
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IF_FEATURE_XARGS_SUPPORT_CONFIRMATION("p") \
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IF_FEATURE_XARGS_SUPPORT_TERMOPT( "x") \
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IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( "0")
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int xargs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int xargs_main(int argc, char **argv)
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{
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int i;
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int child_error = 0;
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char *max_args;
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char *max_chars;
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char *buf;
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unsigned opt;
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int n_max_chars;
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int n_max_arg;
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#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
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char* FAST_FUNC (*read_args)(int, int, char*) = process_stdin;
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#else
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#define read_args process_stdin
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#endif
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INIT_G();
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G.eof_str = NULL;
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opt = getopt32(argv, OPTION_STR, &max_args, &max_chars, &G.eof_str, &G.eof_str);
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/* -E ""? You may wonder why not just omit -E?
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* This is used for portability:
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* old xargs was using "_" as default for -E / -e */
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if ((opt & OPT_EOF_STRING1) && G.eof_str[0] == '\0')
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G.eof_str = NULL;
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if (opt & OPT_ZEROTERM)
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IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin);
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argv += optind;
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argc -= optind;
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if (!argv[0]) {
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/* default behavior is to echo all the filenames */
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*--argv = (char*)"echo";
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argc++;
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}
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/* -s NUM default. fileutils-4.4.2 uses 128k, but I heasitate
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* to use such a big value - first need to change code to use
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* growable buffer instead of fixed one.
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*/
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n_max_chars = 32 * 1024;
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/* Make smaller if system does not allow our default value.
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* The Open Group Base Specifications Issue 6:
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* "The xargs utility shall limit the command line length such that
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* when the command line is invoked, the combined argument
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* and environment lists (see the exec family of functions
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* in the System Interfaces volume of IEEE Std 1003.1-2001)
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* shall not exceed {ARG_MAX}-2048 bytes".
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*/
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{
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long arg_max = 0;
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#if defined _SC_ARG_MAX
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arg_max = sysconf(_SC_ARG_MAX) - 2048;
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#elif defined ARG_MAX
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arg_max = ARG_MAX - 2048;
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#endif
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if (arg_max > 0 && n_max_chars > arg_max)
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n_max_chars = arg_max;
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}
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if (opt & OPT_UPTO_SIZE) {
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n_max_chars = xatou_range(max_chars, 1, INT_MAX);
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}
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/* Account for prepended fixed arguments */
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{
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size_t n_chars = 0;
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for (i = 0; argv[i]; i++) {
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n_chars += strlen(argv[i]) + 1;
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}
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n_max_chars -= n_chars;
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}
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/* Sanity check */
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if (n_max_chars <= 0) {
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bb_error_msg_and_die("can't fit single argument within argument list size limit");
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}
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buf = xzalloc(n_max_chars + 1);
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n_max_arg = n_max_chars;
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if (opt & OPT_UPTO_NUMBER) {
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n_max_arg = xatou_range(max_args, 1, INT_MAX);
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/* Not necessary, we use growable args[]: */
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/* if (n_max_arg > n_max_chars) n_max_arg = n_max_chars */
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}
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/* Allocate pointers for execvp */
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/* We can statically allocate (argc + n_max_arg + 1) elements
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* and do not bother with resizing args[], but on 64-bit machines
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|
* this results in args[] vector which is ~8 times bigger
|
|
* than n_max_chars! That is, with n_max_chars == 20k,
|
|
* args[] will take 160k (!), which will most likely be
|
|
* almost entirely unused.
|
|
*/
|
|
/* See store_param() for matching 256-step growth logic */
|
|
G.args = xmalloc(sizeof(G.args[0]) * ((argc + 0xff) & ~0xff));
|
|
|
|
/* Store the command to be executed, part 1 */
|
|
for (i = 0; argv[i]; i++)
|
|
G.args[i] = argv[i];
|
|
|
|
while (1) {
|
|
char *rem;
|
|
|
|
G.idx = argc;
|
|
rem = read_args(n_max_chars, n_max_arg, buf);
|
|
store_param(NULL);
|
|
|
|
if (!G.args[argc]) {
|
|
if (*rem != '\0')
|
|
bb_error_msg_and_die("argument line too long");
|
|
if (opt & OPT_NO_EMPTY)
|
|
break;
|
|
}
|
|
opt |= OPT_NO_EMPTY;
|
|
|
|
if (opt & (OPT_INTERACTIVE | OPT_VERBOSE)) {
|
|
const char *fmt = " %s" + 1;
|
|
char **args = G.args;
|
|
for (i = 0; args[i]; i++) {
|
|
fprintf(stderr, fmt, args[i]);
|
|
fmt = " %s";
|
|
}
|
|
if (!(opt & OPT_INTERACTIVE))
|
|
bb_putchar_stderr('\n');
|
|
}
|
|
|
|
if (!(opt & OPT_INTERACTIVE) || xargs_ask_confirmation()) {
|
|
child_error = xargs_exec();
|
|
}
|
|
|
|
if (child_error > 0 && child_error != 123) {
|
|
break;
|
|
}
|
|
|
|
overlapping_strcpy(buf, rem);
|
|
} /* while */
|
|
|
|
if (ENABLE_FEATURE_CLEAN_UP) {
|
|
free(G.args);
|
|
free(buf);
|
|
}
|
|
|
|
return child_error;
|
|
}
|
|
|
|
|
|
#ifdef TEST
|
|
|
|
const char *applet_name = "debug stuff usage";
|
|
|
|
void bb_show_usage(void)
|
|
{
|
|
fprintf(stderr, "Usage: %s [-p] [-r] [-t] -[x] [-n max_arg] [-s max_chars]\n",
|
|
applet_name);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
return xargs_main(argc, argv);
|
|
}
|
|
#endif /* TEST */
|