busybox/debianutils/which.c
2006-07-19 21:45:30 +00:00

107 lines
2.2 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Which implementation for busybox
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
* Licensed under the GPL v2, see the file LICENSE in this tarball.
*
* Based on which from debianutils
*/
#include "busybox.h"
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>
static int is_executable_file(char *a, struct stat *b)
{
return (!access(a,X_OK) && !stat(a, b) && S_ISREG(b->st_mode));
}
int which_main(int argc, char **argv)
{
int status;
size_t i, count;
char *path_list;
if (argc <= 1 || **(argv + 1) == '-') {
bb_show_usage();
}
argc--;
path_list = getenv("PATH");
if (path_list != NULL) {
size_t path_len = strlen(path_list);
char *new_list = NULL;
count = 1;
for (i = 0; i <= path_len; i++) {
char *this_i = &path_list[i];
if (*this_i == ':') {
/* ^::[^:] == \.: */
if (!i && (*(this_i + 1) == ':')) {
*this_i = '.';
continue;
}
*this_i = 0;
count++;
/* ^:[^:] == \.0 and [^:]::[^:] == 0\.0 and [^:]:$ == 0\.0 */
if (!i || (*(this_i + 1) == ':') || (i == path_len-1)) {
new_list = xrealloc(new_list, path_len += 1);
if (i) {
memmove(&new_list[i+2], &path_list[i+1], path_len-i);
new_list[i+1] = '.';
memmove(new_list, path_list, i);
} else {
memmove(&new_list[i+1], &path_list[i], path_len-i);
new_list[i] = '.';
}
path_list = new_list;
}
}
}
} else {
path_list = "/bin\0/sbin\0/usr/bin\0/usr/sbin\0/usr/local/bin";
count = 5;
}
status = EXIT_SUCCESS;
while (argc-- > 0) {
struct stat stat_b;
char *buf;
char *path_n;
int found = 0;
argv++;
path_n = path_list;
buf = *argv;
/* if filename is either absolute or contains slashes,
* stat it */
if (strchr(buf, '/') != NULL && is_executable_file(buf, &stat_b)) {
found++;
} else {
/* Couldn't access file and file doesn't contain slashes */
for (i = 0; i < count; i++) {
buf = concat_path_file(path_n, *argv);
if (is_executable_file(buf, &stat_b)) {
found++;
break;
}
free(buf);
path_n += (strlen(path_n) + 1);
}
}
if (found) {
puts(buf);
} else {
status = EXIT_FAILURE;
}
}
bb_fflush_stdout_and_exit(status);
}