-/* minix xargs - Make and execute commands
- * Author: Ian Nicholls: 1 Mar 90 */
-
+/* vi: set sw=4 ts=4: */
/*
- * xargs - Accept words from stdin until, combined with the arguments
- * given on the command line, just fit into the command line limit.
- * Then, execute the result.
- * e.g. ls | xargs compress
- * find . -name '*.s' -print | xargs ar qv libc.a
+ * Mini xargs implementation for busybox
+ * Options are supported: "-prtx -n max_arg -s max_chars -e[ouf_str]"
+ *
+ * (C) 2002,2003 by Vladimir Oleynik <dzo@simtreas.ru>
*
- * flags: -t Print the command just before it is run
- * -l len Use len as maximum line length (default 490, max 1023)
- * -e ending Append ending to the command before executing it.
+ * Special thanks
+ * - Mark Whitley and Glenn McGrath for stimulus to rewrite :)
+ * - Mike Rendell <michael@cs.mun.ca>
+ * and David MacKenzie <djm@gnu.ai.mit.edu>.
*
- * Exits with: 0 No errors.
- * 1 If any system(3) call returns a nonzero status.
- * 2 Usage error
- * 3 Line length too short to contain some single argument.
+ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
*
- * Examples: xargs ar qv libc.a < liborder # Create a new libc.a
- * find . -name '*.s' -print | xargs rm # Remove all .s files
- * find . -type f ! -name '*.Z' \ # Compress old files.
- * -atime +60 -print | xargs compress -v
+ * xargs is described in the Single Unix Specification v3 at
+ * http://www.opengroup.org/onlinepubs/007904975/utilities/xargs.html
*
- * Bugs: If the command contains unquoted wildflags, then the system(3) call
- * call may expand this to larger than the maximum line size.
- * The command is not executed if nothing was read from stdin.
- * xargs may give up too easily when the command returns nonzero.
*/
-#define USAGE "usage: xargs [-t] [-l len] [-e endargs] command [args...]\n"
-#include <errno.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
-#include <getopt.h>
+//kbuild:lib-$(CONFIG_XARGS) += xargs.o
+//config:
+//config:config XARGS
+//config: bool "xargs"
+//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.
+
+#include "libbb.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
+#if !defined(ARG_MAX)
+# define ARG_MAX 470
+#endif
+
+
+#ifdef TEST
+# ifndef ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION
+# define ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION 1
+# endif
+# ifndef ENABLE_FEATURE_XARGS_SUPPORT_QUOTES
+# define ENABLE_FEATURE_XARGS_SUPPORT_QUOTES 1
+# endif
+# ifndef ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT
+# define ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT 1
+# endif
+# ifndef ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
+# define ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM 1
+# endif
+#endif
+
+/*
+ This function has special algorithm.
+ Don't use fork and include to main!
+*/
+static int xargs_exec(char **args)
+{
+ int status;
+
+ status = spawn_and_wait(args);
+ if (status < 0) {
+ bb_simple_perror_msg(args[0]);
+ return errno == ENOENT ? 127 : 126;
+ }
+ if (status == 255) {
+ bb_error_msg("%s: exited with status 255; aborting", args[0]);
+ return 124;
+ }
+ if (status >= 0x180) {
+ bb_error_msg("%s: terminated by signal %d",
+ args[0], status - 0x180);
+ return 125;
+ }
+ if (status)
+ return 123;
+ return 0;
+}
+
+
+typedef struct xlist_t {
+ struct xlist_t *link;
+ size_t length;
+ char xstr[1];
+} xlist_t;
+
+/* 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); })
+
+#if ENABLE_FEATURE_XARGS_SUPPORT_QUOTES
+static xlist_t* process_stdin(xlist_t *list_arg,
+ const char *eof_str, size_t mc, char *buf)
+{
+#define NORM 0
+#define QUOTE 1
+#define BACKSLASH 2
+#define SPACE 4
+ char *s = NULL; /* start of the word */
+ char *p = NULL; /* pointer to end of the word */
+ char q = '\0'; /* quote char */
+ char state = NORM;
+ char eof_str_detected = 0;
+ size_t line_l = 0; /* size of loaded args */
+ xlist_t *cur;
+ xlist_t *prev;
+
+ prev = cur = list_arg;
+ while (cur) {
+ prev = cur;
+ line_l += cur->length;
+ cur = cur->link;
+ }
+
+ while (1) {
+ int c = getchar();
+ if (c == EOF) {
+ if (s)
+ goto unexpected_eof;
+ break;
+ }
+ if (eof_str_detected) /* skip till EOF */
+ continue;
+ if (state == BACKSLASH) {
+ state = NORM;
+ goto set;
+ }
+ if (state == QUOTE) {
+ if (c != q)
+ goto set;
+ q = '\0';
+ state = NORM;
+ } else { /* if (state == NORM) */
+ if (ISSPACE(c)) {
+ if (s) {
+ unexpected_eof:
+ state = SPACE;
+ c = '\0';
+ goto set;
+ }
+ } else {
+ if (s == NULL)
+ s = p = buf;
+ if (c == '\\') {
+ state = BACKSLASH;
+ } else if (c == '\'' || c == '"') {
+ q = c;
+ state = QUOTE;
+ } else {
+ set:
+ if ((size_t)(p - buf) >= mc)
+ bb_error_msg_and_die("argument line too long");
+ *p++ = c;
+ }
+ }
+ }
+ if (state == SPACE) { /* word's delimiter or EOF detected */
+ if (q) {
+ bb_error_msg_and_die("unmatched %s quote",
+ q == '\'' ? "single" : "double");
+ }
+ /* A full word is 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) /* limit stop memory usage */
+ break;
+ }
+ s = NULL;
+ state = NORM;
+ }
+ }
+ return list_arg;
+}
+#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)
+{
+ char eof_str_detected = 0;
+ char *s = NULL; /* start of the word */
+ char *p = NULL; /* pointer to end of the word */
+ size_t line_l = 0; /* size of loaded args */
+ xlist_t *cur;
+ xlist_t *prev;
+
+ prev = cur = list_arg;
+ while (cur) {
+ prev = cur;
+ line_l += cur->length;
+ cur = cur->link;
+ }
+
+ while (1) {
+ int c = getchar();
+ if (c == EOF) {
+ if (s == NULL)
+ break;
+ }
+ if (eof_str_detected) { /* skip till EOF */
+ continue;
+ }
+ if (c == EOF || ISSPACE(c)) {
+ if (s == NULL)
+ 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 */
+ /* A full word is 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) /* limit stop memory usage */
+ break;
+ }
+ s = NULL;
+ }
+ }
+ return list_arg;
+}
+#endif /* FEATURE_XARGS_SUPPORT_QUOTES */
+
+
+#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. */
+static int xargs_ask_confirmation(void)
+{
+ FILE *tty_stream;
+ int c, savec;
+
+ 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);
+ fclose(tty_stream);
+ return (savec == 'y' || savec == 'Y');
+}
+#else
+# define xargs_ask_confirmation() 1
+#endif /* FEATURE_XARGS_SUPPORT_CONFIRMATION */
+
+#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)
+{
+ char *s = NULL; /* start of the word */
+ char *p = NULL; /* pointer to end of the word */
+ size_t line_l = 0; /* size of loaded args */
+ xlist_t *cur;
+ xlist_t *prev;
-#ifndef MAX_ARGLINE
-# define MAX_ARGLINE 1023
+ prev = cur = list_arg;
+ while (cur) {
+ prev = cur;
+ line_l += cur->length;
+ cur = cur->link;
+ }
+
+ while (1) {
+ int c = getchar();
+ if (c == EOF) {
+ 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 */
+ /* A full word is 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) /* limit stop memory usage */
+ break;
+ s = NULL;
+ }
+ }
+ return list_arg;
+}
+#endif /* FEATURE_XARGS_SUPPORT_ZERO_TERM */
+
+/* Correct regardless of combination of CONFIG_xxx */
+enum {
+ OPTBIT_VERBOSE = 0,
+ OPTBIT_NO_EMPTY,
+ OPTBIT_UPTO_NUMBER,
+ OPTBIT_UPTO_SIZE,
+ OPTBIT_EOF_STRING,
+ OPTBIT_EOF_STRING1,
+ IF_FEATURE_XARGS_SUPPORT_CONFIRMATION(OPTBIT_INTERACTIVE,)
+ IF_FEATURE_XARGS_SUPPORT_TERMOPT( OPTBIT_TERMINATE ,)
+ IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( OPTBIT_ZEROTERM ,)
+
+ OPT_VERBOSE = 1 << OPTBIT_VERBOSE ,
+ OPT_NO_EMPTY = 1 << OPTBIT_NO_EMPTY ,
+ OPT_UPTO_NUMBER = 1 << OPTBIT_UPTO_NUMBER,
+ OPT_UPTO_SIZE = 1 << OPTBIT_UPTO_SIZE ,
+ OPT_EOF_STRING = 1 << OPTBIT_EOF_STRING , /* GNU: -e[<param>] */
+ OPT_EOF_STRING1 = 1 << OPTBIT_EOF_STRING1, /* SUS: -E<param> */
+ 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,
+};
+#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")
+
+int xargs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int xargs_main(int argc, char **argv)
+{
+ xlist_t *list = NULL;
+ int child_error = 0;
+ char *max_args;
+ char *max_chars;
+ char *buf;
+ int n_max_arg;
+ const char *eof_str = NULL;
+ 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;
+#else
+#define read_args process_stdin
#endif
-#ifndef min
-# define min(a,b) ((a) < (b) ? (a) : (b))
+
+ opt = getopt32(argv, OPTION_STR, &max_args, &max_chars, &eof_str, &eof_str);
+
+ /* -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_ZEROTERM)
+ IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin);
+
+ argv += optind;
+ argc -= optind;
+ if (!argv[0]) {
+ /* default behavior is to echo all the filenames */
+ *--argv = (char*)"echo";
+ argc++;
+ }
+
+ /* 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 = ARG_MAX; /* might be calling sysconf(_SC_ARG_MAX) */
+ if (n_max_chars < 4*1024); /* paranoia */
+ n_max_chars = 4*1024;
+ n_max_chars -= 2048;
+ /* 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 (n_max_chars > 20 * 1024)
+ n_max_chars = 20 * 1024;
+
+ if (opt & OPT_UPTO_SIZE) {
+ int i;
+ size_t n_chars = 0;
+ n_max_chars = xatoul_range(max_chars, 1, n_max_chars);
+ for (i = 0; argv[i]; i++) {
+ n_chars += strlen(argv[i]) + 1;
+ }
+ n_max_chars -= n_chars;
+ if ((ssize_t)n_max_chars <= 0) {
+ bb_error_msg_and_die("can't fit single argument within argument list size limit");
+ }
+ }
+
+ buf = xmalloc(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;
+ }
+
+ while ((list = read_args(list, eof_str, n_max_chars, buf)) != NULL
+ || !(opt & OPT_NO_EMPTY)
+ ) {
+ char **args;
+ xlist_t *cur;
+ int i, n;
+ size_t n_chars = 0;
+
+ opt |= OPT_NO_EMPTY;
+ n = 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) {
+ break;
+ }
+ }
#endif
-char outlin[MAX_ARGLINE];
-char inlin[MAX_ARGLINE];
-char startlin[MAX_ARGLINE];
-char *ending = NULL;
-char traceflag = 0;
+ /* allocate pointers for execvp */
+ args = xzalloc(sizeof(args[0]) * (argc + n + 1));
+
+ /* store the command to be executed
+ * (taken from the command line) */
+ for (i = 0; argv[i]; i++)
+ args[i] = argv[i];
+ /* (taken from stdin) */
+ for (cur = list; n; cur = cur->link) {
+ args[i++] = cur->xstr;
+ n--;
+ }
+
+ if (opt & (OPT_INTERACTIVE | OPT_VERBOSE)) {
+ for (i = 0; args[i]; i++) {
+ if (i)
+ bb_putchar_stderr(' ');
+ fputs(args[i], stderr);
+ }
+ if (!(opt & OPT_INTERACTIVE))
+ bb_putchar_stderr('\n');
+ }
+
+ if (!(opt & OPT_INTERACTIVE) || xargs_ask_confirmation()) {
+ child_error = xargs_exec(args);
+ }
+
+ /* 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;
+ }
+ } /* while */
+
+ if (ENABLE_FEATURE_CLEAN_UP)
+ 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 xargs_main(int ac, char **av)
+int main(int argc, char **argv)
{
- int outlen, inlen, startlen, endlen=0, i;
- char errflg = 0;
- int maxlin = MAX_ARGLINE;
-
- while ((i = getopt(ac, av, "tl:e:")) != EOF)
- switch (i) {
- case 't': traceflag = 1; break;
- case 'l': maxlin = min(MAX_ARGLINE, atoi(optarg)); break;
- case 'e': ending = optarg; break;
- case '?': errflg++; break;
- }
- if (errflg) {
- fprintf(stderr, USAGE);
- exit(2);
- }
-
- startlin[0] = 0;
- if (optind == ac) {
- strcat(startlin, "echo ");
- }
- else for ( ; optind < ac; optind++) {
- strcat(startlin, av[optind]);
- strcat(startlin, " ");
- }
- startlen = strlen(startlin);
- if (ending) endlen = strlen(ending);
- maxlin = maxlin - 1 - endlen; /* Pre-compute */
-
- strcpy(outlin, startlin);
- outlen = startlen;
-
- while (gets(inlin) != NULL) {
- inlen = strlen(inlin);
- if (maxlin <= (outlen + inlen)) {
- if (outlen == startlen) {
- fprintf(stderr, "%s: Line length too short to process '%s'\n",
- av[0], inlin);
- exit(3);
- }
- if (ending) strcat(outlin, ending);
- if (traceflag) fputs(outlin,stderr);
- errno = 0;
- if (0 != system(outlin)) {
- if (errno != 0) perror("xargs");
- exit(1);
- }
- strcpy(outlin, startlin);
- outlen = startlen;
- }
- strcat(outlin, inlin);
- strcat(outlin, " ");
- outlen = outlen + inlen + 1;
- }
- if (outlen != startlen) {
- if (ending) strcat(outlin, ending);
- if (traceflag) fputs(outlin,stderr);
- errno = 0;
- if (0 != system(outlin)) {
- if (errno != 0) perror("xargs");
- exit(1);
- }
- }
- return 0;
+ return xargs_main(argc, argv);
}
+#endif /* TEST */
projects / oweals / busybox.git / blobdiff