X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=findutils%2Fxargs.c;h=0d1bb43fc89a7e05ee06627342762f0149c1b0d2;hb=df9196d824ea9bca7590edade631362e89b5c6ce;hp=677618dc062bbb032afbf00dc4b9c3823bae670a;hpb=f57674e9a9b0b29102981e1694b76170b78dfb43;p=oweals%2Fbusybox.git

diff --git a/findutils/xargs.c b/findutils/xargs.c
index 677618dc0..0d1bb43fc 100644
--- a/findutils/xargs.c
+++ b/findutils/xargs.c
@@ -1,128 +1,565 @@
+/* vi: set sw=4 ts=4: */
 /*
  * Mini xargs implementation for busybox
- * Only "-prt" options are supported in this version of xargs.
  *
- * (C) 2002 by Vladimir Oleynik <dzo@simtreas.ru>
+ * (C) 2002,2003 by Vladimir Oleynik <dzo@simtreas.ru>
  *
- * Special thanks Mark Whitley for stimul to rewrote :)
+ * 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>.
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * 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
  */
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <getopt.h>
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include "busybox.h"
+//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.
+
+//applet:IF_XARGS(APPLET_NOEXEC(xargs, xargs, BB_DIR_USR_BIN, BB_SUID_DROP, xargs))
+
+//kbuild:lib-$(CONFIG_XARGS) += xargs.o
+
+#include "libbb.h"
+
+/* This is a NOEXEC applet. Be very careful! */
+
+
+//#define dbg_msg(...) bb_error_msg(__VA_ARGS__)
+#define dbg_msg(...) ((void)0)
+
+
+#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
+
+
+struct globals {
+	char **args;
+	const char *eof_str;
+	int idx;
+} FIX_ALIASING;
+#define G (*(struct globals*)&bb_common_bufsiz1)
+#define INIT_G() do { \
+	G.eof_str = NULL; /* need to clear by hand because we are NOEXEC applet */ \
+} while (0)
 
 
 /*
-   This function have special algorithm.
-   Don`t use fork and include to main!
-*/
-static void xargs_exec(char * const * args)
+ * This function has special algorithm.
+ * Don't use fork and include to main!
+ */
+static int xargs_exec(void)
+{
+	int status;
+
+	status = spawn_and_wait(G.args);
+	if (status < 0) {
+		bb_simple_perror_msg(G.args[0]);
+		return errno == ENOENT ? 127 : 126;
+	}
+	if (status == 255) {
+		bb_error_msg("%s: exited with status 255; aborting", G.args[0]);
+		return 124;
+	}
+	if (status >= 0x180) {
+		bb_error_msg("%s: terminated by signal %d",
+			G.args[0], status - 0x180);
+		return 125;
+	}
+	if (status)
+		return 123;
+	return 0;
+}
+
+/* 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); })
+
+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;
+}
+
+/* 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 accomodate 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 char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf)
 {
-	int p;
-	int common[4];  /* shared vfork stack */
-
-	common[0] = 0;
-	if ((p = vfork()) >= 0) {
-		if (p == 0) {
-			/* vfork -- child */
-			execvp(args[0], args);
-			common[0] = errno; /* set error to shared stack */
-			_exit(1);
-		} else {
-			/* vfork -- parent */
-			wait(NULL);
-			if(common[0]) {
-				errno = common[0];
-				perror_msg_and_die("%s", args[0]);
+#define NORM      0
+#define QUOTE     1
+#define BACKSLASH 2
+#define SPACE     4
+	char q = '\0';             /* quote char */
+	char state = NORM;
+	char *s = buf;             /* start of the word */
+	char *p = s + strlen(buf); /* end of the word */
+
+	buf += n_max_chars;        /* past buffer's end */
+
+	/* "goto ret" is used instead of "break" to make control flow
+	 * more obvious: */
+
+	while (1) {
+		int c = getchar();
+		if (c == EOF) {
+			if (p != s)
+				goto close_word;
+			goto ret;
+		}
+		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 (p != s) {
+ close_word:
+					state = SPACE;
+					c = '\0';
+					goto set;
+				}
+			} else {
+				if (c == '\\') {
+					state = BACKSLASH;
+				} else if (c == '\'' || c == '"') {
+					q = c;
+					state = QUOTE;
+				} else {
+ set:
+					*p++ = c;
+				}
 			}
 		}
-	} else {
-		perror_msg_and_die("vfork");
+		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 (G.eof_str) {
+				if (strcmp(s, G.eof_str) == 0) {
+					while (getchar() != EOF)
+						continue;
+					p = s;
+					goto ret;
+				}
+			}
+			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;
+		}
 	}
+ 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 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 xargs_main(int argc, char **argv)
+	buf += n_max_chars;        /* past buffer's end */
+
+	while (1) {
+		int c = getchar();
+		if (c == EOF) {
+			if (p == s)
+				goto ret;
+		}
+		if (c == EOF || ISSPACE(c)) {
+			if (p == s)
+				continue;
+			c = EOF;
+		}
+		*p++ = (c == EOF ? '\0' : c);
+		if (c == EOF) { /* word's delimiter or EOF detected */
+			/* A full word is loaded */
+			if (G.eof_str) {
+				if (strcmp(s, G.eof_str) == 0) {
+					while (getchar() != EOF)
+						continue;
+					p = s;
+					goto ret;
+				}
+			}
+			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_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 *file_to_act_on;
-	char **args;
-	int  i, a;
-	char flg_vi       = 0;    /* verbose |& interactive */
-	char flg_no_empty = 0;
-
-	while ((a = getopt(argc, argv, "prt")) > 0) {
-		switch(a) {
-			case 'p':
-				flg_vi |= 3;
-				break;
-			case 't':
-				flg_vi |= 1;
-				break;
-			case 'r':
-				flg_no_empty = 1;
-				break;
-			default:
-				show_usage();
+	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') {   /* word's delimiter 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_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
+
+//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_CONFIRMATION(
+//usage:     "\n	-p	Ask user whether to run each command"
+//usage:	)
+//usage:     "\n	-r	Don't run command if input is empty"
+//usage:	IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(
+//usage:     "\n	-0	Input is separated by NUL characters"
+//usage:	)
+//usage:     "\n	-t	Print the command on stderr before execution"
+//usage:     "\n	-e[STR]	STR stops input processing"
+//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_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 {
+	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)
+{
+	int i;
+	int child_error = 0;
+	char *max_args;
+	char *max_chars;
+	char *buf;
+	unsigned opt;
+	int n_max_chars;
+	int n_max_arg;
+#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
+	char* FAST_FUNC (*read_args)(int, int, char*) = process_stdin;
+#else
+#define read_args process_stdin
+#endif
+
+	INIT_G();
+
+#if ENABLE_DESKTOP && ENABLE_LONG_OPTS
+	/* For example, Fedora's build system uses --no-run-if-empty */
+	applet_long_options =
+		"no-run-if-empty\0" No_argument "r"
+		;
+#endif
+	opt = getopt32(argv, OPTION_STR, &max_args, &max_chars, &G.eof_str, &G.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) && G.eof_str[0] == '\0')
+		G.eof_str = NULL;
+
+	if (opt & OPT_ZEROTERM)
+		IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin);
 
-	a = argc - optind;
 	argv += optind;
-	if(a==0) {
+	argc -= optind;
+	if (!argv[0]) {
 		/* default behavior is to echo all the filenames */
-		*argv = "/bin/echo";
-		a++;
+		*--argv = (char*)"echo";
+		argc++;
 	}
-	/* allocating pointers for execvp: a*arg, arg from stdin, NULL */
-	args = xcalloc(a + 3, sizeof(char *));
-
-	/* Store the command to be executed (taken from the command line) */
-	for (i = 0; i < a; i++)
-		args[i] = *argv++;
-
-	/* Now, read in one line at a time from stdin, and store this 
-	 * line to be used later as an argument to the command */
-	while ((file_to_act_on = get_line_from_file(stdin)) != NULL) {
-		/* eat the newline off the filename. */
-		chomp(file_to_act_on);
-		if(file_to_act_on[0] != 0 || flg_no_empty == 0) {
-			args[a] = file_to_act_on[0] ? file_to_act_on : NULL;
-			if(flg_vi) {
-				for(i=0; args[i]; i++) {
-					if(i)
-						fputc(' ', stderr);
-					fputs(args[i], stderr);
-				}
-				fprintf(stderr, "%s", ((flg_vi & 2) ? " ?..." : "\n"));
-			}
-			if((flg_vi & 2) == 0 || ask_confirmation() != 0 ) {
-				xargs_exec(args);
+
+	/* -s NUM default. fileutils-4.4.2 uses 128k, but I heasitate
+	 * to use such a big value - first need to change code to use
+	 * growable buffer instead of fixed one.
+	 */
+	n_max_chars = 32 * 1024;
+	/* Make smaller if system does not allow our default value.
+	 * 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".
+	 */
+	{
+		long arg_max = 0;
+#if defined _SC_ARG_MAX
+		arg_max = sysconf(_SC_ARG_MAX) - 2048;
+#elif defined ARG_MAX
+		arg_max = ARG_MAX - 2048;
+#endif
+		if (arg_max > 0 && n_max_chars > arg_max)
+			n_max_chars = arg_max;
+	}
+	if (opt & OPT_UPTO_SIZE) {
+		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;
+	}
+	/* Sanity check */
+	if (n_max_chars <= 0) {
+		bb_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 = 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 */
+	}
+
+	/* Allocate pointers for execvp */
+	/* 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.
+	 */
+	/* 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;
 		}
-		/* clean up */
-		free(file_to_act_on);
+
+		overlapping_strcpy(buf, rem);
+	} /* while */
+
+	if (ENABLE_FEATURE_CLEAN_UP) {
+		free(G.args);
+		free(buf);
 	}
-#ifdef CONFIG_FEATURE_CLEAN_UP
-	free(args);
-#endif
-	return 0;
+
+	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 */