[3320] | 1 | /* vi: set sw=4 ts=4: */
|
---|
| 2 | /*
|
---|
| 3 | * Mini xargs implementation for busybox
|
---|
| 4 | *
|
---|
| 5 | * (C) 2002,2003 by Vladimir Oleynik <dzo@simtreas.ru>
|
---|
| 6 | *
|
---|
| 7 | * Special thanks
|
---|
| 8 | * - Mark Whitley and Glenn McGrath for stimulus to rewrite :)
|
---|
| 9 | * - Mike Rendell <michael@cs.mun.ca>
|
---|
| 10 | * and David MacKenzie <djm@gnu.ai.mit.edu>.
|
---|
| 11 | *
|
---|
| 12 | * Licensed under GPLv2 or later, see file LICENSE in this source tree.
|
---|
| 13 | *
|
---|
| 14 | * xargs is described in the Single Unix Specification v3 at
|
---|
| 15 | * http://www.opengroup.org/onlinepubs/007904975/utilities/xargs.html
|
---|
| 16 | */
|
---|
| 17 |
|
---|
| 18 | //applet:IF_XARGS(APPLET_NOEXEC(xargs, xargs, _BB_DIR_USR_BIN, _BB_SUID_DROP, xargs))
|
---|
| 19 |
|
---|
| 20 | //kbuild:lib-$(CONFIG_XARGS) += xargs.o
|
---|
| 21 |
|
---|
| 22 | //config:config XARGS
|
---|
| 23 | //config: bool "xargs"
|
---|
| 24 | //config: default y
|
---|
| 25 | //config: help
|
---|
| 26 | //config: xargs is used to execute a specified command for
|
---|
| 27 | //config: every item from standard input.
|
---|
| 28 | //config:
|
---|
| 29 | //config:config FEATURE_XARGS_SUPPORT_CONFIRMATION
|
---|
| 30 | //config: bool "Enable -p: prompt and confirmation"
|
---|
| 31 | //config: default y
|
---|
| 32 | //config: depends on XARGS
|
---|
| 33 | //config: help
|
---|
| 34 | //config: Support -p: prompt the user whether to run each command
|
---|
| 35 | //config: line and read a line from the terminal.
|
---|
| 36 | //config:
|
---|
| 37 | //config:config FEATURE_XARGS_SUPPORT_QUOTES
|
---|
| 38 | //config: bool "Enable single and double quotes and backslash"
|
---|
| 39 | //config: default y
|
---|
| 40 | //config: depends on XARGS
|
---|
| 41 | //config: help
|
---|
| 42 | //config: Support quoting in the input.
|
---|
| 43 | //config:
|
---|
| 44 | //config:config FEATURE_XARGS_SUPPORT_TERMOPT
|
---|
| 45 | //config: bool "Enable -x: exit if -s or -n is exceeded"
|
---|
| 46 | //config: default y
|
---|
| 47 | //config: depends on XARGS
|
---|
| 48 | //config: help
|
---|
| 49 | //config: Support -x: exit if the command size (see the -s or -n option)
|
---|
| 50 | //config: is exceeded.
|
---|
| 51 | //config:
|
---|
| 52 | //config:config FEATURE_XARGS_SUPPORT_ZERO_TERM
|
---|
| 53 | //config: bool "Enable -0: NUL-terminated input"
|
---|
| 54 | //config: default y
|
---|
| 55 | //config: depends on XARGS
|
---|
| 56 | //config: help
|
---|
| 57 | //config: Support -0: input items are terminated by a NUL character
|
---|
| 58 | //config: instead of whitespace, and the quotes and backslash
|
---|
| 59 | //config: are not special.
|
---|
| 60 |
|
---|
| 61 | #include "libbb.h"
|
---|
| 62 |
|
---|
| 63 | /* This is a NOEXEC applet. Be very careful! */
|
---|
| 64 |
|
---|
| 65 |
|
---|
| 66 | //#define dbg_msg(...) bb_error_msg(__VA_ARGS__)
|
---|
| 67 | #define dbg_msg(...) ((void)0)
|
---|
| 68 |
|
---|
| 69 |
|
---|
| 70 | #ifdef TEST
|
---|
| 71 | # ifndef ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION
|
---|
| 72 | # define ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION 1
|
---|
| 73 | # endif
|
---|
| 74 | # ifndef ENABLE_FEATURE_XARGS_SUPPORT_QUOTES
|
---|
| 75 | # define ENABLE_FEATURE_XARGS_SUPPORT_QUOTES 1
|
---|
| 76 | # endif
|
---|
| 77 | # ifndef ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT
|
---|
| 78 | # define ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT 1
|
---|
| 79 | # endif
|
---|
| 80 | # ifndef ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
|
---|
| 81 | # define ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM 1
|
---|
| 82 | # endif
|
---|
| 83 | #endif
|
---|
| 84 |
|
---|
| 85 |
|
---|
| 86 | struct globals {
|
---|
| 87 | char **args;
|
---|
| 88 | const char *eof_str;
|
---|
| 89 | int idx;
|
---|
| 90 | } FIX_ALIASING;
|
---|
| 91 | #define G (*(struct globals*)&bb_common_bufsiz1)
|
---|
| 92 | #define INIT_G() do { } while (0)
|
---|
| 93 |
|
---|
| 94 |
|
---|
| 95 | /*
|
---|
| 96 | * This function has special algorithm.
|
---|
| 97 | * Don't use fork and include to main!
|
---|
| 98 | */
|
---|
| 99 | static int xargs_exec(void)
|
---|
| 100 | {
|
---|
| 101 | int status;
|
---|
| 102 |
|
---|
| 103 | status = spawn_and_wait(G.args);
|
---|
| 104 | if (status < 0) {
|
---|
| 105 | bb_simple_perror_msg(G.args[0]);
|
---|
| 106 | return errno == ENOENT ? 127 : 126;
|
---|
| 107 | }
|
---|
| 108 | if (status == 255) {
|
---|
| 109 | bb_error_msg("%s: exited with status 255; aborting", G.args[0]);
|
---|
| 110 | return 124;
|
---|
| 111 | }
|
---|
| 112 | if (status >= 0x180) {
|
---|
| 113 | bb_error_msg("%s: terminated by signal %d",
|
---|
| 114 | G.args[0], status - 0x180);
|
---|
| 115 | return 125;
|
---|
| 116 | }
|
---|
| 117 | if (status)
|
---|
| 118 | return 123;
|
---|
| 119 | return 0;
|
---|
| 120 | }
|
---|
| 121 |
|
---|
| 122 | /* In POSIX/C locale isspace is only these chars: "\t\n\v\f\r" and space.
|
---|
| 123 | * "\t\n\v\f\r" happen to have ASCII codes 9,10,11,12,13.
|
---|
| 124 | */
|
---|
| 125 | #define ISSPACE(a) ({ unsigned char xargs__isspace = (a) - 9; xargs__isspace == (' ' - 9) || xargs__isspace <= (13 - 9); })
|
---|
| 126 |
|
---|
| 127 | static void store_param(char *s)
|
---|
| 128 | {
|
---|
| 129 | /* Grow by 256 elements at once */
|
---|
| 130 | if (!(G.idx & 0xff)) { /* G.idx == N*256 */
|
---|
| 131 | /* Enlarge, make G.args[(N+1)*256 - 1] last valid idx */
|
---|
| 132 | G.args = xrealloc(G.args, sizeof(G.args[0]) * (G.idx + 0x100));
|
---|
| 133 | }
|
---|
| 134 | G.args[G.idx++] = s;
|
---|
| 135 | }
|
---|
| 136 |
|
---|
| 137 | /* process[0]_stdin:
|
---|
| 138 | * Read characters into buf[n_max_chars+1], and when parameter delimiter
|
---|
| 139 | * is seen, store the address of a new parameter to args[].
|
---|
| 140 | * If reading discovers that last chars do not form the complete
|
---|
| 141 | * parameter, the pointer to the first such "tail character" is returned.
|
---|
| 142 | * (buf has extra byte at the end to accomodate terminating NUL
|
---|
| 143 | * of "tail characters" string).
|
---|
| 144 | * Otherwise, the returned pointer points to NUL byte.
|
---|
| 145 | * On entry, buf[] may contain some "seed chars" which are to become
|
---|
| 146 | * the beginning of the first parameter.
|
---|
| 147 | */
|
---|
| 148 |
|
---|
| 149 | #if ENABLE_FEATURE_XARGS_SUPPORT_QUOTES
|
---|
| 150 | static char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf)
|
---|
| 151 | {
|
---|
| 152 | #define NORM 0
|
---|
| 153 | #define QUOTE 1
|
---|
| 154 | #define BACKSLASH 2
|
---|
| 155 | #define SPACE 4
|
---|
| 156 | char q = '\0'; /* quote char */
|
---|
| 157 | char state = NORM;
|
---|
| 158 | char *s = buf; /* start of the word */
|
---|
| 159 | char *p = s + strlen(buf); /* end of the word */
|
---|
| 160 |
|
---|
| 161 | buf += n_max_chars; /* past buffer's end */
|
---|
| 162 |
|
---|
| 163 | /* "goto ret" is used instead of "break" to make control flow
|
---|
| 164 | * more obvious: */
|
---|
| 165 |
|
---|
| 166 | while (1) {
|
---|
| 167 | int c = getchar();
|
---|
| 168 | if (c == EOF) {
|
---|
| 169 | if (p != s)
|
---|
| 170 | goto close_word;
|
---|
| 171 | goto ret;
|
---|
| 172 | }
|
---|
| 173 | if (state == BACKSLASH) {
|
---|
| 174 | state = NORM;
|
---|
| 175 | goto set;
|
---|
| 176 | }
|
---|
| 177 | if (state == QUOTE) {
|
---|
| 178 | if (c != q)
|
---|
| 179 | goto set;
|
---|
| 180 | q = '\0';
|
---|
| 181 | state = NORM;
|
---|
| 182 | } else { /* if (state == NORM) */
|
---|
| 183 | if (ISSPACE(c)) {
|
---|
| 184 | if (p != s) {
|
---|
| 185 | close_word:
|
---|
| 186 | state = SPACE;
|
---|
| 187 | c = '\0';
|
---|
| 188 | goto set;
|
---|
| 189 | }
|
---|
| 190 | } else {
|
---|
| 191 | if (c == '\\') {
|
---|
| 192 | state = BACKSLASH;
|
---|
| 193 | } else if (c == '\'' || c == '"') {
|
---|
| 194 | q = c;
|
---|
| 195 | state = QUOTE;
|
---|
| 196 | } else {
|
---|
| 197 | set:
|
---|
| 198 | *p++ = c;
|
---|
| 199 | }
|
---|
| 200 | }
|
---|
| 201 | }
|
---|
| 202 | if (state == SPACE) { /* word's delimiter or EOF detected */
|
---|
| 203 | if (q) {
|
---|
| 204 | bb_error_msg_and_die("unmatched %s quote",
|
---|
| 205 | q == '\'' ? "single" : "double");
|
---|
| 206 | }
|
---|
| 207 | /* A full word is loaded */
|
---|
| 208 | if (G.eof_str) {
|
---|
| 209 | if (strcmp(s, G.eof_str) == 0) {
|
---|
| 210 | while (getchar() != EOF)
|
---|
| 211 | continue;
|
---|
| 212 | p = s;
|
---|
| 213 | goto ret;
|
---|
| 214 | }
|
---|
| 215 | }
|
---|
| 216 | store_param(s);
|
---|
| 217 | dbg_msg("args[]:'%s'", s);
|
---|
| 218 | s = p;
|
---|
| 219 | n_max_arg--;
|
---|
| 220 | if (n_max_arg == 0) {
|
---|
| 221 | goto ret;
|
---|
| 222 | }
|
---|
| 223 | state = NORM;
|
---|
| 224 | }
|
---|
| 225 | if (p == buf) {
|
---|
| 226 | goto ret;
|
---|
| 227 | }
|
---|
| 228 | }
|
---|
| 229 | ret:
|
---|
| 230 | *p = '\0';
|
---|
| 231 | /* store_param(NULL) - caller will do it */
|
---|
| 232 | dbg_msg("return:'%s'", s);
|
---|
| 233 | return s;
|
---|
| 234 | }
|
---|
| 235 | #else
|
---|
| 236 | /* The variant does not support single quotes, double quotes or backslash */
|
---|
| 237 | static char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf)
|
---|
| 238 | {
|
---|
| 239 | char *s = buf; /* start of the word */
|
---|
| 240 | char *p = s + strlen(buf); /* end of the word */
|
---|
| 241 |
|
---|
| 242 | buf += n_max_chars; /* past buffer's end */
|
---|
| 243 |
|
---|
| 244 | while (1) {
|
---|
| 245 | int c = getchar();
|
---|
| 246 | if (c == EOF) {
|
---|
| 247 | if (p == s)
|
---|
| 248 | goto ret;
|
---|
| 249 | }
|
---|
| 250 | if (c == EOF || ISSPACE(c)) {
|
---|
| 251 | if (p == s)
|
---|
| 252 | continue;
|
---|
| 253 | c = EOF;
|
---|
| 254 | }
|
---|
| 255 | *p++ = (c == EOF ? '\0' : c);
|
---|
| 256 | if (c == EOF) { /* word's delimiter or EOF detected */
|
---|
| 257 | /* A full word is loaded */
|
---|
| 258 | if (G.eof_str) {
|
---|
| 259 | if (strcmp(s, G.eof_str) == 0) {
|
---|
| 260 | while (getchar() != EOF)
|
---|
| 261 | continue;
|
---|
| 262 | p = s;
|
---|
| 263 | goto ret;
|
---|
| 264 | }
|
---|
| 265 | }
|
---|
| 266 | store_param(s);
|
---|
| 267 | dbg_msg("args[]:'%s'", s);
|
---|
| 268 | s = p;
|
---|
| 269 | n_max_arg--;
|
---|
| 270 | if (n_max_arg == 0) {
|
---|
| 271 | goto ret;
|
---|
| 272 | }
|
---|
| 273 | }
|
---|
| 274 | if (p == buf) {
|
---|
| 275 | goto ret;
|
---|
| 276 | }
|
---|
| 277 | }
|
---|
| 278 | ret:
|
---|
| 279 | *p = '\0';
|
---|
| 280 | /* store_param(NULL) - caller will do it */
|
---|
| 281 | dbg_msg("return:'%s'", s);
|
---|
| 282 | return s;
|
---|
| 283 | }
|
---|
| 284 | #endif /* FEATURE_XARGS_SUPPORT_QUOTES */
|
---|
| 285 |
|
---|
| 286 | #if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
|
---|
| 287 | static char* FAST_FUNC process0_stdin(int n_max_chars, int n_max_arg, char *buf)
|
---|
| 288 | {
|
---|
| 289 | char *s = buf; /* start of the word */
|
---|
| 290 | char *p = s + strlen(buf); /* end of the word */
|
---|
| 291 |
|
---|
| 292 | buf += n_max_chars; /* past buffer's end */
|
---|
| 293 |
|
---|
| 294 | while (1) {
|
---|
| 295 | int c = getchar();
|
---|
| 296 | if (c == EOF) {
|
---|
| 297 | if (p == s)
|
---|
| 298 | goto ret;
|
---|
| 299 | c = '\0';
|
---|
| 300 | }
|
---|
| 301 | *p++ = c;
|
---|
| 302 | if (c == '\0') { /* word's delimiter or EOF detected */
|
---|
| 303 | /* A full word is loaded */
|
---|
| 304 | store_param(s);
|
---|
| 305 | dbg_msg("args[]:'%s'", s);
|
---|
| 306 | s = p;
|
---|
| 307 | n_max_arg--;
|
---|
| 308 | if (n_max_arg == 0) {
|
---|
| 309 | goto ret;
|
---|
| 310 | }
|
---|
| 311 | }
|
---|
| 312 | if (p == buf) {
|
---|
| 313 | goto ret;
|
---|
| 314 | }
|
---|
| 315 | }
|
---|
| 316 | ret:
|
---|
| 317 | *p = '\0';
|
---|
| 318 | /* store_param(NULL) - caller will do it */
|
---|
| 319 | dbg_msg("return:'%s'", s);
|
---|
| 320 | return s;
|
---|
| 321 | }
|
---|
| 322 | #endif /* FEATURE_XARGS_SUPPORT_ZERO_TERM */
|
---|
| 323 |
|
---|
| 324 | #if ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION
|
---|
| 325 | /* Prompt the user for a response, and
|
---|
| 326 | if the user responds affirmatively, return true;
|
---|
| 327 | otherwise, return false. Uses "/dev/tty", not stdin. */
|
---|
| 328 | static int xargs_ask_confirmation(void)
|
---|
| 329 | {
|
---|
| 330 | FILE *tty_stream;
|
---|
| 331 | int c, savec;
|
---|
| 332 |
|
---|
| 333 | tty_stream = xfopen_for_read(CURRENT_TTY);
|
---|
| 334 | fputs(" ?...", stderr);
|
---|
| 335 | fflush_all();
|
---|
| 336 | c = savec = getc(tty_stream);
|
---|
| 337 | while (c != EOF && c != '\n')
|
---|
| 338 | c = getc(tty_stream);
|
---|
| 339 | fclose(tty_stream);
|
---|
| 340 | return (savec == 'y' || savec == 'Y');
|
---|
| 341 | }
|
---|
| 342 | #else
|
---|
| 343 | # define xargs_ask_confirmation() 1
|
---|
| 344 | #endif
|
---|
| 345 |
|
---|
| 346 | //usage:#define xargs_trivial_usage
|
---|
| 347 | //usage: "[OPTIONS] [PROG ARGS]"
|
---|
| 348 | //usage:#define xargs_full_usage "\n\n"
|
---|
| 349 | //usage: "Run PROG on every item given by stdin\n"
|
---|
| 350 | //usage: "\nOptions:"
|
---|
| 351 | //usage: IF_FEATURE_XARGS_SUPPORT_CONFIRMATION(
|
---|
| 352 | //usage: "\n -p Ask user whether to run each command"
|
---|
| 353 | //usage: )
|
---|
| 354 | //usage: "\n -r Don't run command if input is empty"
|
---|
| 355 | //usage: IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(
|
---|
| 356 | //usage: "\n -0 Input is separated by NUL characters"
|
---|
| 357 | //usage: )
|
---|
| 358 | //usage: "\n -t Print the command on stderr before execution"
|
---|
| 359 | //usage: "\n -e[STR] STR stops input processing"
|
---|
| 360 | //usage: "\n -n N Pass no more than N args to PROG"
|
---|
| 361 | //usage: "\n -s N Pass command line of no more than N bytes"
|
---|
| 362 | //usage: IF_FEATURE_XARGS_SUPPORT_TERMOPT(
|
---|
| 363 | //usage: "\n -x Exit if size is exceeded"
|
---|
| 364 | //usage: )
|
---|
| 365 | //usage:#define xargs_example_usage
|
---|
| 366 | //usage: "$ ls | xargs gzip\n"
|
---|
| 367 | //usage: "$ find . -name '*.c' -print | xargs rm\n"
|
---|
| 368 |
|
---|
| 369 | /* Correct regardless of combination of CONFIG_xxx */
|
---|
| 370 | enum {
|
---|
| 371 | OPTBIT_VERBOSE = 0,
|
---|
| 372 | OPTBIT_NO_EMPTY,
|
---|
| 373 | OPTBIT_UPTO_NUMBER,
|
---|
| 374 | OPTBIT_UPTO_SIZE,
|
---|
| 375 | OPTBIT_EOF_STRING,
|
---|
| 376 | OPTBIT_EOF_STRING1,
|
---|
| 377 | IF_FEATURE_XARGS_SUPPORT_CONFIRMATION(OPTBIT_INTERACTIVE,)
|
---|
| 378 | IF_FEATURE_XARGS_SUPPORT_TERMOPT( OPTBIT_TERMINATE ,)
|
---|
| 379 | IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( OPTBIT_ZEROTERM ,)
|
---|
| 380 |
|
---|
| 381 | OPT_VERBOSE = 1 << OPTBIT_VERBOSE ,
|
---|
| 382 | OPT_NO_EMPTY = 1 << OPTBIT_NO_EMPTY ,
|
---|
| 383 | OPT_UPTO_NUMBER = 1 << OPTBIT_UPTO_NUMBER,
|
---|
| 384 | OPT_UPTO_SIZE = 1 << OPTBIT_UPTO_SIZE ,
|
---|
| 385 | OPT_EOF_STRING = 1 << OPTBIT_EOF_STRING , /* GNU: -e[<param>] */
|
---|
| 386 | OPT_EOF_STRING1 = 1 << OPTBIT_EOF_STRING1, /* SUS: -E<param> */
|
---|
| 387 | OPT_INTERACTIVE = IF_FEATURE_XARGS_SUPPORT_CONFIRMATION((1 << OPTBIT_INTERACTIVE)) + 0,
|
---|
| 388 | OPT_TERMINATE = IF_FEATURE_XARGS_SUPPORT_TERMOPT( (1 << OPTBIT_TERMINATE )) + 0,
|
---|
| 389 | OPT_ZEROTERM = IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( (1 << OPTBIT_ZEROTERM )) + 0,
|
---|
| 390 | };
|
---|
| 391 | #define OPTION_STR "+trn:s:e::E:" \
|
---|
| 392 | IF_FEATURE_XARGS_SUPPORT_CONFIRMATION("p") \
|
---|
| 393 | IF_FEATURE_XARGS_SUPPORT_TERMOPT( "x") \
|
---|
| 394 | IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( "0")
|
---|
| 395 |
|
---|
| 396 | int xargs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
---|
| 397 | int xargs_main(int argc, char **argv)
|
---|
| 398 | {
|
---|
| 399 | int i;
|
---|
| 400 | int child_error = 0;
|
---|
| 401 | char *max_args;
|
---|
| 402 | char *max_chars;
|
---|
| 403 | char *buf;
|
---|
| 404 | unsigned opt;
|
---|
| 405 | int n_max_chars;
|
---|
| 406 | int n_max_arg;
|
---|
| 407 | #if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
|
---|
| 408 | char* FAST_FUNC (*read_args)(int, int, char*) = process_stdin;
|
---|
| 409 | #else
|
---|
| 410 | #define read_args process_stdin
|
---|
| 411 | #endif
|
---|
| 412 |
|
---|
| 413 | INIT_G();
|
---|
| 414 |
|
---|
| 415 | G.eof_str = NULL;
|
---|
| 416 | opt = getopt32(argv, OPTION_STR, &max_args, &max_chars, &G.eof_str, &G.eof_str);
|
---|
| 417 |
|
---|
| 418 | /* -E ""? You may wonder why not just omit -E?
|
---|
| 419 | * This is used for portability:
|
---|
| 420 | * old xargs was using "_" as default for -E / -e */
|
---|
| 421 | if ((opt & OPT_EOF_STRING1) && G.eof_str[0] == '\0')
|
---|
| 422 | G.eof_str = NULL;
|
---|
| 423 |
|
---|
| 424 | if (opt & OPT_ZEROTERM)
|
---|
| 425 | IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin);
|
---|
| 426 |
|
---|
| 427 | argv += optind;
|
---|
| 428 | argc -= optind;
|
---|
| 429 | if (!argv[0]) {
|
---|
| 430 | /* default behavior is to echo all the filenames */
|
---|
| 431 | *--argv = (char*)"echo";
|
---|
| 432 | argc++;
|
---|
| 433 | }
|
---|
| 434 |
|
---|
| 435 | /* -s NUM default. fileutils-4.4.2 uses 128k, but I heasitate
|
---|
| 436 | * to use such a big value - first need to change code to use
|
---|
| 437 | * growable buffer instead of fixed one.
|
---|
| 438 | */
|
---|
| 439 | n_max_chars = 32 * 1024;
|
---|
| 440 | /* Make smaller if system does not allow our default value.
|
---|
| 441 | * The Open Group Base Specifications Issue 6:
|
---|
| 442 | * "The xargs utility shall limit the command line length such that
|
---|
| 443 | * when the command line is invoked, the combined argument
|
---|
| 444 | * and environment lists (see the exec family of functions
|
---|
| 445 | * in the System Interfaces volume of IEEE Std 1003.1-2001)
|
---|
| 446 | * shall not exceed {ARG_MAX}-2048 bytes".
|
---|
| 447 | */
|
---|
| 448 | {
|
---|
| 449 | long arg_max = 0;
|
---|
| 450 | #if defined _SC_ARG_MAX
|
---|
| 451 | arg_max = sysconf(_SC_ARG_MAX) - 2048;
|
---|
| 452 | #elif defined ARG_MAX
|
---|
| 453 | arg_max = ARG_MAX - 2048;
|
---|
| 454 | #endif
|
---|
| 455 | if (arg_max > 0 && n_max_chars > arg_max)
|
---|
| 456 | n_max_chars = arg_max;
|
---|
| 457 | }
|
---|
| 458 | if (opt & OPT_UPTO_SIZE) {
|
---|
| 459 | n_max_chars = xatou_range(max_chars, 1, INT_MAX);
|
---|
| 460 | }
|
---|
| 461 | /* Account for prepended fixed arguments */
|
---|
| 462 | {
|
---|
| 463 | size_t n_chars = 0;
|
---|
| 464 | for (i = 0; argv[i]; i++) {
|
---|
| 465 | n_chars += strlen(argv[i]) + 1;
|
---|
| 466 | }
|
---|
| 467 | n_max_chars -= n_chars;
|
---|
| 468 | }
|
---|
| 469 | /* Sanity check */
|
---|
| 470 | if (n_max_chars <= 0) {
|
---|
| 471 | bb_error_msg_and_die("can't fit single argument within argument list size limit");
|
---|
| 472 | }
|
---|
| 473 |
|
---|
| 474 | buf = xzalloc(n_max_chars + 1);
|
---|
| 475 |
|
---|
| 476 | n_max_arg = n_max_chars;
|
---|
| 477 | if (opt & OPT_UPTO_NUMBER) {
|
---|
| 478 | n_max_arg = xatou_range(max_args, 1, INT_MAX);
|
---|
| 479 | /* Not necessary, we use growable args[]: */
|
---|
| 480 | /* if (n_max_arg > n_max_chars) n_max_arg = n_max_chars */
|
---|
| 481 | }
|
---|
| 482 |
|
---|
| 483 | /* Allocate pointers for execvp */
|
---|
| 484 | /* We can statically allocate (argc + n_max_arg + 1) elements
|
---|
| 485 | * and do not bother with resizing args[], but on 64-bit machines
|
---|
| 486 | * this results in args[] vector which is ~8 times bigger
|
---|
| 487 | * than n_max_chars! That is, with n_max_chars == 20k,
|
---|
| 488 | * args[] will take 160k (!), which will most likely be
|
---|
| 489 | * almost entirely unused.
|
---|
| 490 | */
|
---|
| 491 | /* See store_param() for matching 256-step growth logic */
|
---|
| 492 | G.args = xmalloc(sizeof(G.args[0]) * ((argc + 0xff) & ~0xff));
|
---|
| 493 |
|
---|
| 494 | /* Store the command to be executed, part 1 */
|
---|
| 495 | for (i = 0; argv[i]; i++)
|
---|
| 496 | G.args[i] = argv[i];
|
---|
| 497 |
|
---|
| 498 | while (1) {
|
---|
| 499 | char *rem;
|
---|
| 500 |
|
---|
| 501 | G.idx = argc;
|
---|
| 502 | rem = read_args(n_max_chars, n_max_arg, buf);
|
---|
| 503 | store_param(NULL);
|
---|
| 504 |
|
---|
| 505 | if (!G.args[argc]) {
|
---|
| 506 | if (*rem != '\0')
|
---|
| 507 | bb_error_msg_and_die("argument line too long");
|
---|
| 508 | if (opt & OPT_NO_EMPTY)
|
---|
| 509 | break;
|
---|
| 510 | }
|
---|
| 511 | opt |= OPT_NO_EMPTY;
|
---|
| 512 |
|
---|
| 513 | if (opt & (OPT_INTERACTIVE | OPT_VERBOSE)) {
|
---|
| 514 | const char *fmt = " %s" + 1;
|
---|
| 515 | char **args = G.args;
|
---|
| 516 | for (i = 0; args[i]; i++) {
|
---|
| 517 | fprintf(stderr, fmt, args[i]);
|
---|
| 518 | fmt = " %s";
|
---|
| 519 | }
|
---|
| 520 | if (!(opt & OPT_INTERACTIVE))
|
---|
| 521 | bb_putchar_stderr('\n');
|
---|
| 522 | }
|
---|
| 523 |
|
---|
| 524 | if (!(opt & OPT_INTERACTIVE) || xargs_ask_confirmation()) {
|
---|
| 525 | child_error = xargs_exec();
|
---|
| 526 | }
|
---|
| 527 |
|
---|
| 528 | if (child_error > 0 && child_error != 123) {
|
---|
| 529 | break;
|
---|
| 530 | }
|
---|
| 531 |
|
---|
| 532 | overlapping_strcpy(buf, rem);
|
---|
| 533 | } /* while */
|
---|
| 534 |
|
---|
| 535 | if (ENABLE_FEATURE_CLEAN_UP) {
|
---|
| 536 | free(G.args);
|
---|
| 537 | free(buf);
|
---|
| 538 | }
|
---|
| 539 |
|
---|
| 540 | return child_error;
|
---|
| 541 | }
|
---|
| 542 |
|
---|
| 543 |
|
---|
| 544 | #ifdef TEST
|
---|
| 545 |
|
---|
| 546 | const char *applet_name = "debug stuff usage";
|
---|
| 547 |
|
---|
| 548 | void bb_show_usage(void)
|
---|
| 549 | {
|
---|
| 550 | fprintf(stderr, "Usage: %s [-p] [-r] [-t] -[x] [-n max_arg] [-s max_chars]\n",
|
---|
| 551 | applet_name);
|
---|
| 552 | exit(EXIT_FAILURE);
|
---|
| 553 | }
|
---|
| 554 |
|
---|
| 555 | int main(int argc, char **argv)
|
---|
| 556 | {
|
---|
| 557 | return xargs_main(argc, argv);
|
---|
| 558 | }
|
---|
| 559 | #endif /* TEST */
|
---|