busybox/findutils/xargs.c
2003-10-09 11:06:45 +00:00

262 lines
6.2 KiB
C

/*
* Mini xargs implementation for busybox
* Only "-prt" options are supported in this version of xargs.
*
* (C) 2002 by Vladimir Oleynik <dzo@simtreas.ru>
* (C) 2003 by Glenn McGrath <bug1@optushome.com.au>
*
* Special thanks Mark Whitley for stimul to rewrote :)
*
* 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
*
*
* Reference:
* http://www.opengroup.org/onlinepubs/007904975/utilities/xargs.html
*
*
* BUGS:
* - E option doesnt allow spaces before argument
* - exit value of isnt correct
* - doesnt print quoted string properly
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <getopt.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/wait.h>
#include "busybox.h"
/*
This function have special algorithm.
Don`t use fork and include to main!
*/
static int xargs_exec(char **args)
{
pid_t p;
volatile int exec_errno; /* shared vfork stack */
exec_errno = 0;
p = vfork();
if (p < 0) {
bb_perror_msg_and_die("vfork");
} else if (p == 0) {
/* vfork -- child */
execvp(args[0], args);
exec_errno = errno; /* set error to shared stack */
_exit(1);
} else {
/* vfork -- parent */
int status;
while (wait(&status) == (pid_t) - 1) {
if (errno != EINTR) {
break;
}
}
if (exec_errno) {
errno = exec_errno;
bb_perror_msg("%s", args[0]);
return exec_errno == ENOENT ? 127 : 126;
} else if (WEXITSTATUS(status) == 255) {
bb_error_msg("%s: exited with status 255; aborting", args[0]);
return 124;
} else if (WIFSTOPPED(status)) {
bb_error_msg("%s: stopped by signal %d", args[0],
WSTOPSIG(status));
return 125;
} else if (WIFSIGNALED(status)) {
bb_error_msg("%s: terminated by signal %d", args[0],
WTERMSIG(status));
return 125;
} else if (WEXITSTATUS(status)) {
return 123;
} else {
return 0;
}
}
}
#define OPT_VERBOSE 0x1
#define OPT_TERMINATE 0x2
#define OPT_UPTO_NUMBER 0x4
#define OPT_UPTO_SIZE 0x8
#define OPT_EOF_STRING 0x10
int xargs_main(int argc, char **argv)
{
#ifdef CONFIG_FEATURE_XARGS_FANCY
char *s_max_args = NULL;
char *s_line_size = NULL;
#endif
char *eof_string = "_";
unsigned long flg;
int line_size;
unsigned int max_args = LINE_MAX;
char *line_buffer = NULL;
char *line_buffer_ptr_ptr;
char *old_arg = NULL;
char **args;
char *args_entry_ptr;
int i;
int a;
#if 0
/* Default to maximum line length */
if (LINE_MAX > ARG_MAX - 2048) {
/* Minimum command line length */
line_size = LINE_MAX;
} else {
/* Maximum command line length */
line_size = ARG_MAX = 2048;
}
#else
line_size = LINE_MAX;
#endif
#ifndef CONFIG_FEATURE_XARGS_FANCY
flg = bb_getopt_ulflags(argc, argv, "+t");
#else
flg = bb_getopt_ulflags(argc, argv, "+txn:s:E::", &s_max_args, &s_line_size, &eof_string);
if (s_line_size) {
line_size = bb_xgetularg10_bnd(s_max_args, 1, line_size);
}
if (s_max_args) {
max_args = bb_xgetularg10(s_max_args);
}
#endif
a = argc - optind;
argv += optind;
if (a == 0) {
/* default behavior is to echo all the filenames */
*argv = "echo";
a++;
}
/* allocating pointers for execvp: a*arg, arg from stdin, NULL */
args = xcalloc(a + 2, sizeof(char *));
/* Store the command to be executed (taken from the command line) */
for (i = 0; i < a; i++) {
line_size -= strlen(*argv) + 1;
args[i] = *argv++;
}
if (line_size < 1) {
bb_error_msg_and_die("can not fit single argument within argument list size limit");
}
args[i] = xmalloc(line_size);
args_entry_ptr = args[i];
/* Now, read in one line at a time from stdin, and store this
* line to be used later as an argument to the command */
do {
char *line_buffer_ptr = NULL;
unsigned int arg_count = 0;
unsigned int arg_size = 0;
*args_entry_ptr = '\0';
/* Get the required number of entries from stdin */
do {
/* (Re)fill the line buffer */
if (line_buffer == NULL) {
line_buffer = bb_get_chomped_line_from_file(stdin);
if (line_buffer == NULL) {
/* EOF, exit outer loop */
break;
}
line_buffer_ptr =
strtok_r(line_buffer, " \t", &line_buffer_ptr_ptr);
} else {
if (old_arg) {
line_buffer_ptr = old_arg;
old_arg = NULL;
} else {
line_buffer_ptr =
strtok_r(NULL, " \t", &line_buffer_ptr_ptr);
}
}
/* If no arguments left go back and get another line */
if (line_buffer_ptr == NULL) {
free(line_buffer);
line_buffer = NULL;
continue;
}
#ifdef CONFIG_FEATURE_XARGS_FANCY
if (eof_string && (strcmp(line_buffer_ptr, eof_string) == 0)) {
#else
if (strcmp(line_buffer_ptr, eof_string) == 0) {
#endif
/* logical EOF, exit outer loop */
line_buffer = NULL;
break;
}
/* Check the next argument will fit */
arg_size += 1 + strlen(line_buffer_ptr);
if (arg_size > line_size) {
if ((arg_count == 0)
#ifdef CONFIG_FEATURE_XARGS_FANCY
|| ((flg & OPT_TERMINATE) && (arg_count != max_args))) {
#else
) {
#endif
bb_error_msg_and_die("argument line too long");
}
old_arg = line_buffer_ptr;
break;
}
/* Add the entry to our pre-allocated space */
strcat(args_entry_ptr, line_buffer_ptr);
strcat(args_entry_ptr, " ");
arg_count++;
} while (arg_count < max_args);
/* Remove the last space */
args_entry_ptr[arg_size - 1] = '\0';
if (*args_entry_ptr != '\0') {
if (flg & OPT_VERBOSE) {
for (i = 0; args[i]; i++) {
if (i) {
fputc(' ', stderr);
}
fputs(args[i], stderr);
}
fputc('\n', stderr);
}
xargs_exec(args);
}
} while (line_buffer);
#ifdef CONFIG_FEATURE_CLEAN_UP
free(args);
#endif
return 0;
}