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/* SPDX-License-Identifier: LGPL-2.1+ */
#include "alloc-util.h"
#include "env-file.h"
#include "fd-util.h"
#include "fs-util.h"
#include "macro.h"
#include "os-util.h"
#include "string-util.h"
#include "strv.h"
int path_is_os_tree(const char *path) {
int r;
assert(path);
/* Does the path exist at all? If not, generate an error immediately. This is useful so that a missing root dir
* always results in -ENOENT, and we can properly distuingish the case where the whole root doesn't exist from
* the case where just the os-release file is missing. */
if (laccess(path, F_OK) < 0)
return -errno;
/* We use {/etc|/usr/lib}/os-release as flag file if something is an OS */
r = open_os_release(path, NULL, NULL);
if (r == -ENOENT) /* We got nothing */
return 0;
if (r < 0)
return r;
return 1;
}
int open_os_release(const char *root, char **ret_path, int *ret_fd) {
_cleanup_free_ char *q = NULL;
const char *p;
int k;
FOREACH_STRING(p, "/etc/os-release", "/usr/lib/os-release") {
k = chase_symlinks(p, root, CHASE_PREFIX_ROOT|(ret_fd ? CHASE_OPEN : 0), (ret_path ? &q : NULL));
if (k != -ENOENT)
break;
}
if (k < 0)
return k;
if (ret_fd) {
int real_fd;
/* Convert the O_PATH fd into a proper, readable one */
real_fd = fd_reopen(k, O_RDONLY|O_CLOEXEC|O_NOCTTY);
safe_close(k);
if (real_fd < 0)
return real_fd;
*ret_fd = real_fd;
}
if (ret_path)
*ret_path = TAKE_PTR(q);
return 0;
}
int fopen_os_release(const char *root, char **ret_path, FILE **ret_file) {
_cleanup_free_ char *p = NULL;
_cleanup_close_ int fd = -1;
FILE *f;
int r;
if (!ret_file)
return open_os_release(root, ret_path, NULL);
r = open_os_release(root, ret_path ? &p : NULL, &fd);
if (r < 0)
return r;
f = fdopen(fd, "r");
if (!f)
return -errno;
fd = -1;
*ret_file = f;
if (ret_path)
*ret_path = TAKE_PTR(p);
return 0;
}
int parse_os_release(const char *root, ...) {
_cleanup_fclose_ FILE *f = NULL;
_cleanup_free_ char *p = NULL;
va_list ap;
int r;
r = fopen_os_release(root, &p, &f);
if (r < 0)
return r;
va_start(ap, root);
r = parse_env_filev(f, p, ap);
va_end(ap);
return r;
}
int load_os_release_pairs(const char *root, char ***ret) {
_cleanup_fclose_ FILE *f = NULL;
_cleanup_free_ char *p = NULL;
int r;
r = fopen_os_release(root, &p, &f);
if (r < 0)
return r;
return load_env_file_pairs(f, p, ret);
}
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