X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=findutils%2Fxargs.c;h=72631580323e1858a52334b7baa8415c1f1c1df4;hb=e5897d041d704a40efc8480cb2a72ef6843d0642;hp=f5dbc7825c2dc4f4fea616e0ae5f0f9eb94933f9;hpb=8531d76a15890c2c535908ce888b2e2aed35b172;p=oweals%2Fbusybox.git diff --git a/findutils/xargs.c b/findutils/xargs.c index f5dbc7825..726315803 100644 --- a/findutils/xargs.c +++ b/findutils/xargs.c @@ -1,7 +1,6 @@ /* vi: set sw=4 ts=4: */ /* * Mini xargs implementation for busybox - * Options are supported: "-prtx -n max_arg -s max_chars -e[ouf_str]" * * (C) 2002,2003 by Vladimir Oleynik * @@ -10,26 +9,79 @@ * - Mike Rendell * and David MacKenzie . * - * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. + * Licensed under GPLv2 or later, see file LICENSE in this source tree. * * xargs is described in the Single Unix Specification v3 at * http://www.opengroup.org/onlinepubs/007904975/utilities/xargs.html - * */ +//config:config XARGS +//config: bool "xargs (7.2 kb)" +//config: default y +//config: help +//config: xargs is used to execute a specified command for +//config: every item from standard input. +//config: +//config:config FEATURE_XARGS_SUPPORT_CONFIRMATION +//config: bool "Enable -p: prompt and confirmation" +//config: default y +//config: depends on XARGS +//config: help +//config: Support -p: prompt the user whether to run each command +//config: line and read a line from the terminal. +//config: +//config:config FEATURE_XARGS_SUPPORT_QUOTES +//config: bool "Enable single and double quotes and backslash" +//config: default y +//config: depends on XARGS +//config: help +//config: Support quoting in the input. +//config: +//config:config FEATURE_XARGS_SUPPORT_TERMOPT +//config: bool "Enable -x: exit if -s or -n is exceeded" +//config: default y +//config: depends on XARGS +//config: help +//config: Support -x: exit if the command size (see the -s or -n option) +//config: is exceeded. +//config: +//config:config FEATURE_XARGS_SUPPORT_ZERO_TERM +//config: bool "Enable -0: NUL-terminated input" +//config: default y +//config: depends on XARGS +//config: help +//config: Support -0: input items are terminated by a NUL character +//config: instead of whitespace, and the quotes and backslash +//config: are not special. +//config: +//config:config FEATURE_XARGS_SUPPORT_REPL_STR +//config: bool "Enable -I STR: string to replace" +//config: default y +//config: depends on XARGS +//config: help +//config: Support -I STR and -i[STR] options. +//config: +//config:config FEATURE_XARGS_SUPPORT_PARALLEL +//config: bool "Enable -P N: processes to run in parallel" +//config: default y +//config: depends on XARGS +//config: +//config:config FEATURE_XARGS_SUPPORT_ARGS_FILE +//config: bool "Enable -a FILE: use FILE instead of stdin" +//config: default y +//config: depends on XARGS + +//applet:IF_XARGS(APPLET_NOEXEC(xargs, xargs, BB_DIR_USR_BIN, BB_SUID_DROP, xargs)) + +//kbuild:lib-$(CONFIG_XARGS) += xargs.o #include "libbb.h" +#include "common_bufsiz.h" /* This is a NOEXEC applet. Be very careful! */ -/* COMPAT: SYSV version defaults size (and has a max value of) to 470. - We try to make it as large as possible. */ -#if !defined(ARG_MAX) && defined(_SC_ARG_MAX) -#define ARG_MAX sysconf (_SC_ARG_MAX) -#endif -#ifndef ARG_MAX -#define ARG_MAX 470 -#endif +//#define dbg_msg(...) bb_error_msg(__VA_ARGS__) +#define dbg_msg(...) ((void)0) #ifdef TEST @@ -47,102 +99,203 @@ # endif #endif + +struct globals { + char **args; +#if ENABLE_FEATURE_XARGS_SUPPORT_REPL_STR + char **argv; + const char *repl_str; + char eol_ch; +#endif + const char *eof_str; + int idx; +#if ENABLE_FEATURE_XARGS_SUPPORT_PARALLEL + int running_procs; + int max_procs; +#endif + smalluint xargs_exitcode; +} FIX_ALIASING; +#define G (*(struct globals*)bb_common_bufsiz1) +#define INIT_G() do { \ + setup_common_bufsiz(); \ + G.eof_str = NULL; /* need to clear by hand because we are NOEXEC applet */ \ + G.idx = 0; \ + IF_FEATURE_XARGS_SUPPORT_PARALLEL(G.running_procs = 0;) \ + IF_FEATURE_XARGS_SUPPORT_PARALLEL(G.max_procs = 1;) \ + G.xargs_exitcode = 0; \ + IF_FEATURE_XARGS_SUPPORT_REPL_STR(G.repl_str = "{}";) \ + IF_FEATURE_XARGS_SUPPORT_REPL_STR(G.eol_ch = '\n';) \ +} while (0) + + /* - This function has special algorithm. - Don't use fork and include to main! -*/ -static int xargs_exec(char **args) + * Returns 0 if xargs should continue (but may set G.xargs_exitcode to 123). + * Else sets G.xargs_exitcode to error code and returns nonzero. + * + * If G.max_procs == 0, performs final waitpid() loop for all children. + */ +static int xargs_exec(void) { int status; - status = spawn_and_wait(args); +#if !ENABLE_FEATURE_XARGS_SUPPORT_PARALLEL + status = spawn_and_wait(G.args); +#else + if (G.max_procs == 1) { + status = spawn_and_wait(G.args); + } else { + pid_t pid; + int wstat; + again: + if (G.running_procs >= G.max_procs) + pid = safe_waitpid(-1, &wstat, 0); + else + pid = wait_any_nohang(&wstat); + if (pid > 0) { + /* We may have children we don't know about: + * sh -c 'sleep 1 & exec xargs ...' + * Do not make G.running_procs go negative. + */ + if (G.running_procs != 0) + G.running_procs--; + status = WIFSIGNALED(wstat) + ? 0x180 + WTERMSIG(wstat) + : WEXITSTATUS(wstat); + if (status > 0 && status < 255) { + /* See below why 123 does not abort */ + G.xargs_exitcode = 123; + status = 0; + } + if (status == 0) + goto again; /* maybe we have more children? */ + /* else: "bad" status, will bail out */ + } else if (G.max_procs != 0) { + /* Not in final waitpid() loop, + * and G.running_procs < G.max_procs: start more procs + */ + status = spawn(G.args); + /* here "status" actually holds pid, or -1 */ + if (status > 0) { + G.running_procs++; + status = 0; + } + /* else: status == -1 (failed to fork or exec) */ + } else { + /* final waitpid() loop: must be ECHILD "no more children" */ + status = 0; + } + } +#endif + /* Manpage: + * """xargs exits with the following status: + * 0 if it succeeds + * 123 if any invocation of the command exited with status 1-125 + * 124 if the command exited with status 255 + * ("""If any invocation of the command exits with a status of 255, + * xargs will stop immediately without reading any further input. + * An error message is issued on stderr when this happens.""") + * 125 if the command is killed by a signal + * 126 if the command cannot be run + * 127 if the command is not found + * 1 if some other error occurred.""" + */ if (status < 0) { - bb_simple_perror_msg(args[0]); - return errno == ENOENT ? 127 : 126; + bb_simple_perror_msg(G.args[0]); + status = (errno == ENOENT) ? 127 : 126; } - if (status == 255) { - bb_error_msg("%s: exited with status 255; aborting", args[0]); - return 124; + else if (status >= 0x180) { + bb_error_msg("'%s' terminated by signal %u", + G.args[0], status - 0x180); + status = 125; } - if (status >= 0x180) { - bb_error_msg("%s: terminated by signal %d", - args[0], status - 0x180); - return 125; + else if (status != 0) { + if (status == 255) { + bb_error_msg("%s: exited with status 255; aborting", G.args[0]); + status = 124; + goto ret; + } + /* "123 if any invocation of the command exited with status 1-125" + * This implies that nonzero exit code is remembered, + * but does not cause xargs to stop: we return 0. + */ + G.xargs_exitcode = 123; + status = 0; } - if (status) - return 123; - return 0; + ret: + if (status != 0) + G.xargs_exitcode = status; + return status; } +/* In POSIX/C locale isspace is only these chars: "\t\n\v\f\r" and space. + * "\t\n\v\f\r" happen to have ASCII codes 9,10,11,12,13. + */ +#define ISSPACE(a) ({ unsigned char xargs__isspace = (a) - 9; xargs__isspace == (' ' - 9) || xargs__isspace <= (13 - 9); }) -typedef struct xlist_t { - struct xlist_t *link; - size_t length; - char xstr[1]; -} xlist_t; - -static smallint eof_stdin_detected; +static void store_param(char *s) +{ + /* Grow by 256 elements at once */ + if (!(G.idx & 0xff)) { /* G.idx == N*256? */ + /* Enlarge, make G.args[(N+1)*256 - 1] last valid idx */ + G.args = xrealloc(G.args, sizeof(G.args[0]) * (G.idx + 0x100)); + } + G.args[G.idx++] = s; +} -#define ISBLANK(c) ((c) == ' ' || (c) == '\t') -#define ISSPACE(c) (ISBLANK(c) || (c) == '\n' || (c) == '\r' \ - || (c) == '\f' || (c) == '\v') +/* process[0]_stdin: + * Read characters into buf[n_max_chars+1], and when parameter delimiter + * is seen, store the address of a new parameter to args[]. + * If reading discovers that last chars do not form the complete + * parameter, the pointer to the first such "tail character" is returned. + * (buf has extra byte at the end to accommodate terminating NUL + * of "tail characters" string). + * Otherwise, the returned pointer points to NUL byte. + * On entry, buf[] may contain some "seed chars" which are to become + * the beginning of the first parameter. + */ #if ENABLE_FEATURE_XARGS_SUPPORT_QUOTES -static xlist_t *process_stdin(xlist_t *list_arg, - const char *eof_str, size_t mc, char *buf) +static char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf) { #define NORM 0 #define QUOTE 1 #define BACKSLASH 2 #define SPACE 4 - - char *s = NULL; /* start word */ - char *p = NULL; /* pointer to end word */ - char q = '\0'; /* quote char */ + char q = '\0'; /* quote char */ char state = NORM; - char eof_str_detected = 0; - size_t line_l = 0; /* size loaded args line */ - int c; /* current char */ - xlist_t *cur; - xlist_t *prev; + char *s = buf; /* start of the word */ + char *p = s + strlen(buf); /* end of the word */ - prev = cur = list_arg; - while (1) { - if (!cur) break; - prev = cur; - line_l += cur->length; - cur = cur->link; - } + buf += n_max_chars; /* past buffer's end */ + + /* "goto ret" is used instead of "break" to make control flow + * more obvious: */ - while (!eof_stdin_detected) { - c = getchar(); + while (1) { + int c = getchar(); if (c == EOF) { - eof_stdin_detected = 1; - if (s) - goto unexpected_eof; - break; + if (p != s) + goto close_word; + goto ret; } - if (eof_str_detected) - continue; if (state == BACKSLASH) { state = NORM; goto set; - } else if (state == QUOTE) { + } + if (state == QUOTE) { if (c != q) goto set; q = '\0'; state = NORM; } else { /* if (state == NORM) */ if (ISSPACE(c)) { - if (s) { - unexpected_eof: + if (p != s) { + close_word: state = SPACE; c = '\0'; goto set; } } else { - if (s == NULL) - s = p = buf; if (c == '\\') { state = BACKSLASH; } else if (c == '\'' || c == '"') { @@ -150,8 +303,6 @@ static xlist_t *process_stdin(xlist_t *list_arg, state = QUOTE; } else { set: - if ((size_t)(p - buf) >= mc) - bb_error_msg_and_die("argument line too long"); *p++ = c; } } @@ -161,185 +312,236 @@ static xlist_t *process_stdin(xlist_t *list_arg, bb_error_msg_and_die("unmatched %s quote", q == '\'' ? "single" : "double"); } - /* word loaded */ - if (eof_str) { - eof_str_detected = (strcmp(s, eof_str) == 0); - } - if (!eof_str_detected) { - size_t length = (p - buf); - /* Dont xzalloc - it can be quite big */ - cur = xmalloc(offsetof(xlist_t, xstr) + length); - cur->link = NULL; - cur->length = length; - memcpy(cur->xstr, s, length); - if (prev == NULL) { - list_arg = cur; - } else { - prev->link = cur; - } - prev = cur; - line_l += length; - if (line_l > mc) { - /* stop memory usage :-) */ - break; + /* A full word is loaded */ + if (G.eof_str) { + if (strcmp(s, G.eof_str) == 0) { + while (getchar() != EOF) + continue; + p = s; + goto ret; } } - s = NULL; + store_param(s); + dbg_msg("args[]:'%s'", s); + s = p; + n_max_arg--; + if (n_max_arg == 0) { + goto ret; + } state = NORM; } + if (p == buf) { + goto ret; + } } - return list_arg; + ret: + *p = '\0'; + /* store_param(NULL) - caller will do it */ + dbg_msg("return:'%s'", s); + return s; } #else /* The variant does not support single quotes, double quotes or backslash */ -static xlist_t *process_stdin(xlist_t *list_arg, - const char *eof_str, size_t mc, char *buf) +static char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf) { + char *s = buf; /* start of the word */ + char *p = s + strlen(buf); /* end of the word */ - int c; /* current char */ - char eof_str_detected = 0; - char *s = NULL; /* start word */ - char *p = NULL; /* pointer to end word */ - size_t line_l = 0; /* size loaded args line */ - xlist_t *cur; - xlist_t *prev; + buf += n_max_chars; /* past buffer's end */ - prev = cur = list_arg; while (1) { - if (!cur) break; - prev = cur; - line_l += cur->length; - cur = cur->link; - } - - while (!eof_stdin_detected) { - c = getchar(); + int c = getchar(); if (c == EOF) { - eof_stdin_detected = 1; + if (p == s) + goto ret; } - if (eof_str_detected) - continue; if (c == EOF || ISSPACE(c)) { - if (s == NULL) + if (p == s) continue; c = EOF; } - if (s == NULL) - s = p = buf; - if ((size_t)(p - buf) >= mc) - bb_error_msg_and_die("argument line too long"); *p++ = (c == EOF ? '\0' : c); if (c == EOF) { /* word's delimiter or EOF detected */ - /* word loaded */ - if (eof_str) { - eof_str_detected = (strcmp(s, eof_str) == 0); - } - if (!eof_str_detected) { - size_t length = (p - buf); - /* Dont xzalloc - it can be quite big */ - cur = xmalloc(offsetof(xlist_t, xstr) + length); - cur->link = NULL; - cur->length = length; - memcpy(cur->xstr, s, length); - if (prev == NULL) { - list_arg = cur; - } else { - prev->link = cur; + /* A full word is loaded */ + if (G.eof_str) { + if (strcmp(s, G.eof_str) == 0) { + while (getchar() != EOF) + continue; + p = s; + goto ret; } - prev = cur; - line_l += length; - if (line_l > mc) { - /* stop memory usage :-) */ - break; - } - s = NULL; + } + store_param(s); + dbg_msg("args[]:'%s'", s); + s = p; + n_max_arg--; + if (n_max_arg == 0) { + goto ret; } } + if (p == buf) { + goto ret; + } } - return list_arg; + ret: + *p = '\0'; + /* store_param(NULL) - caller will do it */ + dbg_msg("return:'%s'", s); + return s; } #endif /* FEATURE_XARGS_SUPPORT_QUOTES */ +#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM +static char* FAST_FUNC process0_stdin(int n_max_chars, int n_max_arg, char *buf) +{ + char *s = buf; /* start of the word */ + char *p = s + strlen(buf); /* end of the word */ + + buf += n_max_chars; /* past buffer's end */ + + while (1) { + int c = getchar(); + if (c == EOF) { + if (p == s) + goto ret; + c = '\0'; + } + *p++ = c; + if (c == '\0') { /* NUL or EOF detected */ + /* A full word is loaded */ + store_param(s); + dbg_msg("args[]:'%s'", s); + s = p; + n_max_arg--; + if (n_max_arg == 0) { + goto ret; + } + } + if (p == buf) { + goto ret; + } + } + ret: + *p = '\0'; + /* store_param(NULL) - caller will do it */ + dbg_msg("return:'%s'", s); + return s; +} +#endif /* FEATURE_XARGS_SUPPORT_ZERO_TERM */ + +#if ENABLE_FEATURE_XARGS_SUPPORT_REPL_STR +/* + * Used if -I was specified. + * In this mode, words aren't appended to PROG ARGS. + * Instead, entire input line is read, then string + * in every PROG and ARG is replaced with the line: + * echo -e "ho ho\nhi" | xargs -I_ cmd __ _ + * results in "cmd 'ho hoho ho' 'ho ho'"; "cmd 'hihi' 'hi'". + * -n MAX_ARGS seems to be ignored. + * Tested with GNU findutils 4.5.10. + */ +//FIXME: n_max_chars is not handled the same way as in GNU findutils. +//FIXME: quoting is not implemented. +static char* FAST_FUNC process_stdin_with_replace(int n_max_chars, int n_max_arg UNUSED_PARAM, char *buf) +{ + int i; + char *end, *p; + + /* Free strings from last invocation, if any */ + for (i = 0; G.args && G.args[i]; i++) + if (G.args[i] != G.argv[i]) + free(G.args[i]); + + end = buf + n_max_chars; + p = buf; + + while (1) { + int c = getchar(); + if (c == EOF || c == G.eol_ch) { + if (p == buf) + goto ret; /* empty line */ + c = '\0'; + } + *p++ = c; + if (c == '\0') { /* EOL or EOF detected */ + i = 0; + while (G.argv[i]) { + char *arg = G.argv[i]; + int count = count_strstr(arg, G.repl_str); + if (count != 0) + arg = xmalloc_substitute_string(arg, count, G.repl_str, buf); + store_param(arg); + dbg_msg("args[]:'%s'", arg); + i++; + } + p = buf; + goto ret; + } + if (p == end) { + goto ret; + } + } + ret: + *p = '\0'; + /* store_param(NULL) - caller will do it */ + dbg_msg("return:'%s'", buf); + return buf; +} +#endif #if ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION /* Prompt the user for a response, and - if the user responds affirmatively, return true; - otherwise, return false. Uses "/dev/tty", not stdin. */ + * if user responds affirmatively, return true; + * otherwise, return false. Uses "/dev/tty", not stdin. + */ static int xargs_ask_confirmation(void) { FILE *tty_stream; - int c, savec; + int r; tty_stream = xfopen_for_read(CURRENT_TTY); + fputs(" ?...", stderr); - fflush_all(); - c = savec = getc(tty_stream); - while (c != EOF && c != '\n') - c = getc(tty_stream); + r = bb_ask_y_confirmation_FILE(tty_stream); + fclose(tty_stream); - return (savec == 'y' || savec == 'Y'); + + return r; } #else # define xargs_ask_confirmation() 1 -#endif /* FEATURE_XARGS_SUPPORT_CONFIRMATION */ +#endif -#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM -static xlist_t *process0_stdin(xlist_t *list_arg, - const char *eof_str UNUSED_PARAM, size_t mc, char *buf) -{ - int c; /* current char */ - char *s = NULL; /* start word */ - char *p = NULL; /* pointer to end word */ - size_t line_l = 0; /* size loaded args line */ - xlist_t *cur; - xlist_t *prev; - - prev = cur = list_arg; - while (1) { - if (!cur) break; - prev = cur; - line_l += cur->length; - cur = cur->link; - } - - while (!eof_stdin_detected) { - c = getchar(); - if (c == EOF) { - eof_stdin_detected = 1; - if (s == NULL) - break; - c = '\0'; - } - if (s == NULL) - s = p = buf; - if ((size_t)(p - buf) >= mc) - bb_error_msg_and_die("argument line too long"); - *p++ = c; - if (c == '\0') { /* word's delimiter or EOF detected */ - /* word loaded */ - size_t length = (p - buf); - /* Dont xzalloc - it can be quite big */ - cur = xmalloc(offsetof(xlist_t, xstr) + length); - cur->link = NULL; - cur->length = length; - memcpy(cur->xstr, s, length); - if (prev == NULL) { - list_arg = cur; - } else { - prev->link = cur; - } - prev = cur; - line_l += length; - if (line_l > mc) { - /* stop memory usage :-) */ - break; - } - s = NULL; - } - } - return list_arg; -} -#endif /* FEATURE_XARGS_SUPPORT_ZERO_TERM */ +//usage:#define xargs_trivial_usage +//usage: "[OPTIONS] [PROG ARGS]" +//usage:#define xargs_full_usage "\n\n" +//usage: "Run PROG on every item given by stdin\n" +//usage: IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( +//usage: "\n -0 Input is separated by NULs" +//usage: ) +//usage: IF_FEATURE_XARGS_SUPPORT_ARGS_FILE( +//usage: "\n -a FILE Read from FILE instead of stdin" +//usage: ) +//usage: "\n -r Don't run command if input is empty" +//usage: "\n -t Print the command on stderr before execution" +//usage: IF_FEATURE_XARGS_SUPPORT_CONFIRMATION( +//usage: "\n -p Ask user whether to run each command" +//usage: ) +//usage: "\n -E STR,-e[STR] STR stops input processing" +//usage: IF_FEATURE_XARGS_SUPPORT_REPL_STR( +//usage: "\n -I STR Replace STR within PROG ARGS with input line" +//usage: ) +//usage: "\n -n N Pass no more than N args to PROG" +//usage: "\n -s N Pass command line of no more than N bytes" +//usage: IF_FEATURE_XARGS_SUPPORT_PARALLEL( +//usage: "\n -P N Run up to N PROGs in parallel" +//usage: ) +//usage: IF_FEATURE_XARGS_SUPPORT_TERMOPT( +//usage: "\n -x Exit if size is exceeded" +//usage: ) +//usage:#define xargs_example_usage +//usage: "$ ls | xargs gzip\n" +//usage: "$ find . -name '*.c' -print | xargs rm\n" /* Correct regardless of combination of CONFIG_xxx */ enum { @@ -352,6 +554,8 @@ enum { IF_FEATURE_XARGS_SUPPORT_CONFIRMATION(OPTBIT_INTERACTIVE,) IF_FEATURE_XARGS_SUPPORT_TERMOPT( OPTBIT_TERMINATE ,) IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( OPTBIT_ZEROTERM ,) + IF_FEATURE_XARGS_SUPPORT_REPL_STR( OPTBIT_REPLSTR ,) + IF_FEATURE_XARGS_SUPPORT_REPL_STR( OPTBIT_REPLSTR1 ,) OPT_VERBOSE = 1 << OPTBIT_VERBOSE , OPT_NO_EMPTY = 1 << OPTBIT_NO_EMPTY , @@ -362,151 +566,192 @@ enum { OPT_INTERACTIVE = IF_FEATURE_XARGS_SUPPORT_CONFIRMATION((1 << OPTBIT_INTERACTIVE)) + 0, OPT_TERMINATE = IF_FEATURE_XARGS_SUPPORT_TERMOPT( (1 << OPTBIT_TERMINATE )) + 0, OPT_ZEROTERM = IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( (1 << OPTBIT_ZEROTERM )) + 0, + OPT_REPLSTR = IF_FEATURE_XARGS_SUPPORT_REPL_STR( (1 << OPTBIT_REPLSTR )) + 0, + OPT_REPLSTR1 = IF_FEATURE_XARGS_SUPPORT_REPL_STR( (1 << OPTBIT_REPLSTR1 )) + 0, }; #define OPTION_STR "+trn:s:e::E:" \ IF_FEATURE_XARGS_SUPPORT_CONFIRMATION("p") \ IF_FEATURE_XARGS_SUPPORT_TERMOPT( "x") \ - IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( "0") + IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( "0") \ + IF_FEATURE_XARGS_SUPPORT_REPL_STR( "I:i::") \ + IF_FEATURE_XARGS_SUPPORT_PARALLEL( "P:+") \ + IF_FEATURE_XARGS_SUPPORT_ARGS_FILE( "a:") int xargs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; -int xargs_main(int argc, char **argv) +int xargs_main(int argc UNUSED_PARAM, char **argv) { - char **args; - int i, n; - xlist_t *list = NULL; - xlist_t *cur; - int child_error = 0; - char *max_args, *max_chars; - int n_max_arg; - size_t n_chars = 0; - long orig_arg_max; - const char *eof_str = NULL; + int initial_idx; + int i; + char *max_args; + char *max_chars; + char *buf; unsigned opt; - size_t n_max_chars; -#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM - xlist_t* (*read_args)(xlist_t*, const char*, size_t, char*) = process_stdin; + int n_max_chars; + int n_max_arg; +#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM \ + || ENABLE_FEATURE_XARGS_SUPPORT_REPL_STR + char* FAST_FUNC (*read_args)(int, int, char*) = process_stdin; #else #define read_args process_stdin #endif + IF_FEATURE_XARGS_SUPPORT_ARGS_FILE(char *opt_a = NULL;) - opt = getopt32(argv, OPTION_STR, &max_args, &max_chars, &eof_str, &eof_str); + INIT_G(); + + opt = getopt32long(argv, OPTION_STR, + "no-run-if-empty\0" No_argument "r", + &max_args, &max_chars, &G.eof_str, &G.eof_str + IF_FEATURE_XARGS_SUPPORT_REPL_STR(, &G.repl_str, &G.repl_str) + IF_FEATURE_XARGS_SUPPORT_PARALLEL(, &G.max_procs) + IF_FEATURE_XARGS_SUPPORT_ARGS_FILE(, &opt_a) + ); + +#if ENABLE_FEATURE_XARGS_SUPPORT_PARALLEL + if (G.max_procs <= 0) /* -P0 means "run lots of them" */ + G.max_procs = 100; /* let's not go crazy high */ +#endif + +#if ENABLE_FEATURE_XARGS_SUPPORT_ARGS_FILE + if (opt_a) + xmove_fd(xopen(opt_a, O_RDONLY), 0); +#endif /* -E ""? You may wonder why not just omit -E? * This is used for portability: * old xargs was using "_" as default for -E / -e */ - if ((opt & OPT_EOF_STRING1) && eof_str[0] == '\0') - eof_str = NULL; + if ((opt & OPT_EOF_STRING1) && G.eof_str[0] == '\0') + G.eof_str = NULL; - if (opt & OPT_ZEROTERM) - IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin); + if (opt & OPT_ZEROTERM) { + IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin;) + IF_FEATURE_XARGS_SUPPORT_REPL_STR(G.eol_ch = '\0';) + } argv += optind; - argc -= optind; - if (!argc) { + //argc -= optind; + if (!argv[0]) { /* default behavior is to echo all the filenames */ - *argv = (char*)"echo"; - argc++; + *--argv = (char*)"echo"; + //argc++; } - orig_arg_max = ARG_MAX; - if (orig_arg_max == -1) - orig_arg_max = LONG_MAX; - orig_arg_max -= 2048; /* POSIX.2 requires subtracting 2048 */ + /* + * The Open Group Base Specifications Issue 6: + * "The xargs utility shall limit the command line length such that + * when the command line is invoked, the combined argument + * and environment lists (see the exec family of functions + * in the System Interfaces volume of IEEE Std 1003.1-2001) + * shall not exceed {ARG_MAX}-2048 bytes". + */ + n_max_chars = bb_arg_max(); + if (n_max_chars > 32 * 1024) + n_max_chars = 32 * 1024; + /* + * POSIX suggests substracting 2048 bytes from sysconf(_SC_ARG_MAX) + * so that the process may safely modify its environment. + */ + n_max_chars -= 2048; if (opt & OPT_UPTO_SIZE) { - n_max_chars = xatoul_range(max_chars, 1, orig_arg_max); - for (i = 0; i < argc; i++) { - n_chars += strlen(*argv) + 1; - } - if (n_max_chars < n_chars) { - bb_error_msg_and_die("can't fit single argument within argument list size limit"); + n_max_chars = xatou_range(max_chars, 1, INT_MAX); + } + /* Account for prepended fixed arguments */ + { + size_t n_chars = 0; + for (i = 0; argv[i]; i++) { + n_chars += strlen(argv[i]) + 1; } n_max_chars -= n_chars; - } else { - /* Sanity check for systems with huge ARG_MAX defines (e.g., Suns which - have it at 1 meg). Things will work fine with a large ARG_MAX but it - will probably hurt the system more than it needs to; an array of this - size is allocated. */ - if (orig_arg_max > 20 * 1024) - orig_arg_max = 20 * 1024; - n_max_chars = orig_arg_max; } - max_chars = xmalloc(n_max_chars); + /* Sanity check */ + if (n_max_chars <= 0) { + bb_simple_error_msg_and_die("can't fit single argument within argument list size limit"); + } + buf = xzalloc(n_max_chars + 1); + + n_max_arg = n_max_chars; if (opt & OPT_UPTO_NUMBER) { - n_max_arg = xatoul_range(max_args, 1, INT_MAX); - } else { - n_max_arg = n_max_chars; + n_max_arg = xatou_range(max_args, 1, INT_MAX); + /* Not necessary, we use growable args[]: */ + /* if (n_max_arg > n_max_chars) n_max_arg = n_max_chars */ } - while ((list = read_args(list, eof_str, n_max_chars, max_chars)) != NULL || - !(opt & OPT_NO_EMPTY)) - { +#if ENABLE_FEATURE_XARGS_SUPPORT_REPL_STR + if (opt & (OPT_REPLSTR | OPT_REPLSTR1)) { + /* + * -I: + * Unmodified args are kept in G.argv[i], + * G.args[i] receives malloced G.argv[i] with replaced + * with input line. Setting this up: + */ + G.args = NULL; + G.argv = argv; + read_args = process_stdin_with_replace; + /* Make -I imply -r. GNU findutils seems to do the same: */ + /* (otherwise "echo -n | xargs -I% echo %" would SEGV) */ opt |= OPT_NO_EMPTY; - n = 0; - n_chars = 0; -#if ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT - for (cur = list; cur;) { - n_chars += cur->length; - n++; - cur = cur->link; - if (n_chars > n_max_chars || (n == n_max_arg && cur)) { - if (opt & OPT_TERMINATE) - bb_error_msg_and_die("argument list too long"); - break; - } - } -#else - for (cur = list; cur; cur = cur->link) { - n_chars += cur->length; - n++; - if (n_chars > n_max_chars || n == n_max_arg) { + } else +#endif + { + /* Store the command to be executed, part 1. + * We can statically allocate (argc + n_max_arg + 1) elements + * and do not bother with resizing args[], but on 64-bit machines + * 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. + */ + for (i = 0; argv[i]; i++) + store_param(argv[i]); + } + + initial_idx = G.idx; + while (1) { + char *rem; + + G.idx = initial_idx; + rem = read_args(n_max_chars, n_max_arg, buf); + store_param(NULL); + + if (!G.args[initial_idx]) { /* not even one ARG was added? */ + if (*rem != '\0') + bb_simple_error_msg_and_die("argument line too long"); + if (opt & OPT_NO_EMPTY) break; - } - } -#endif /* FEATURE_XARGS_SUPPORT_TERMOPT */ - - /* allocate pointers for execvp: - argc*arg, n*arg from stdin, NULL */ - args = xzalloc((n + argc + 1) * sizeof(char *)); - - /* store the command to be executed - (taken from the command line) */ - for (i = 0; i < argc; i++) - args[i] = argv[i]; - /* (taken from stdin) */ - for (cur = list; n; cur = cur->link) { - args[i++] = cur->xstr; - n--; } + 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++) { - if (i) - fputc(' ', stderr); - fputs(args[i], stderr); + fprintf(stderr, fmt, args[i]); + fmt = " %s"; } if (!(opt & OPT_INTERACTIVE)) - fputc('\n', stderr); + bb_putchar_stderr('\n'); } + if (!(opt & OPT_INTERACTIVE) || xargs_ask_confirmation()) { - child_error = xargs_exec(args); + if (xargs_exec() != 0) + break; /* G.xargs_exitcode is set by xargs_exec() */ } - /* clean up */ - for (i = argc; args[i]; i++) { - cur = list; - list = list->link; - free(cur); - } - free(args); - if (child_error > 0 && child_error != 123) { - break; - } + overlapping_strcpy(buf, rem); } /* while */ - if (ENABLE_FEATURE_CLEAN_UP) - free(max_chars); - return child_error; + + if (ENABLE_FEATURE_CLEAN_UP) { + free(G.args); + free(buf); + } + +#if ENABLE_FEATURE_XARGS_SUPPORT_PARALLEL + G.max_procs = 0; + xargs_exec(); /* final waitpid() loop */ +#endif + + return G.xargs_exitcode; }