return NULL;
}
-
/*
- * Return the realpath(3) of the path even if the last directory token does not
- * exist. For example, with /tmp/test1/test2, if test2/ does not exist but the
- * /tmp/test1 does, the real path is returned. In normal time, realpath(3)
- * fails if the end point directory does not exist.
+ * Make a full resolution of the given path even if it doesn't exist.
+ * This function uses the utils_partial_realpath function to resolve
+ * symlinks and relatives paths at the start of the string, and
+ * implements functionnalities to resolve the './' and '../' strings
+ * in the middle of a path. This function is only necessary because
+ * realpath(3) does not accept to resolve unexistent paths.
+ * The returned string was allocated in the function, it is thus of
+ * the responsibility of the caller to free this memory.
*/
LTTNG_HIDDEN
char *utils_expand_path(const char *path)
{
- const char *end_path = NULL;
- char *next, *cut_path = NULL, *expanded_path = NULL;
+ char *next, *previous, *slash, *start_path, *absolute_path = NULL;
/* Safety net */
if (path == NULL) {
goto error;
}
- /* Allocate memory for the expanded path */
- expanded_path = zmalloc(PATH_MAX);
- if (expanded_path == NULL) {
+ /* Allocate memory for the absolute_path */
+ absolute_path = zmalloc(PATH_MAX);
+ if (absolute_path == NULL) {
PERROR("zmalloc expand path");
goto error;
}
- /* If given path is already absolute */
- if (*path == '/') {
- strncpy(expanded_path, path, PATH_MAX);
- /* Else, we have some work to do */
+ /*
+ * If the path is not already absolute nor explicitly relative,
+ * consider we're in the current directory
+ */
+ if (*path != '/' && strncmp(path, "./", 2) != 0 &&
+ strncmp(path, "../", 3) != 0) {
+ snprintf(absolute_path, PATH_MAX, "./%s", path);
+ /* Else, we just copy the path */
} else {
- /* Pointer to the last char of the path */
- const char *last_char = path + strlen(path) - 1;
+ strncpy(absolute_path, path, PATH_MAX);
+ }
- end_path = path;
+ /* Resolve partially our path */
+ absolute_path = utils_partial_realpath(absolute_path,
+ absolute_path, PATH_MAX);
- /* Split part that will be resolved by realpath (relative path from
- * current directory using ./ or ../ only) and part that could not
- * (directory names)
- */
- while ((next = strpbrk(end_path, "/")) && (next != last_char)) {
- end_path = next + 1;
- if (strncmp(end_path, "./", 2) != 0 &&
- strncmp(end_path, "../", 3) != 0) {
- break;
- }
- }
+ /* As long as we find '/./' in the working_path string */
+ while ((next = strstr(absolute_path, "/./"))) {
- /* If this is the end of the string, and we still can resolve it */
- if (strncmp(end_path, "..\0", 3) == 0 ||
- strncmp(end_path, ".\0", 2) == 0) {
- end_path += strlen(end_path);
- }
+ /* We prepare the start_path not containing it */
+ start_path = strndup(absolute_path, next - absolute_path);
- /* If the end part is the whole path, we are in the current dir */
- if (end_path == path) {
- cut_path = strdup(".");
- /* Else, cut the resolvable part from original path */
- } else {
- cut_path = strndup(path, end_path - path);
- }
+ /* And we concatenate it with the part after this string */
+ snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 2);
- /* Resolve the canonical path of the first part of the path */
- expanded_path = realpath((char *)cut_path, expanded_path);
- if (expanded_path == NULL) {
- switch (errno) {
- case ENOENT:
- ERR("%s: No such file or directory", cut_path);
- break;
- default:
- PERROR("realpath utils expand path");
- break;
- }
- goto error;
- }
+ free(start_path);
+ }
- /* Add end part to expanded path if not empty */
- if (*end_path != 0) {
- strncat(expanded_path, "/", PATH_MAX - strlen(expanded_path) - 1);
- strncat(expanded_path, end_path,
- PATH_MAX - strlen(expanded_path) - 1);
+ /* As long as we find '/../' in the working_path string */
+ while ((next = strstr(absolute_path, "/../"))) {
+ /* We find the last level of directory */
+ previous = absolute_path;
+ while ((slash = strpbrk(previous, "/")) && slash != next) {
+ previous = slash + 1;
}
- }
- /* Resolve the internal './' and '../' strings */
- next = utils_resolve_relative(expanded_path);
- if (next == NULL) {
- goto error;
+ /* Then we prepare the start_path not containing it */
+ start_path = strndup(absolute_path, previous - absolute_path);
+
+ /* And we concatenate it with the part after the '/../' */
+ snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 4);
+
+ /* We can free the memory used for the start path*/
+ free(start_path);
+
+ /* Then we verify for symlinks using partial_realpath */
+ absolute_path = utils_partial_realpath(absolute_path,
+ absolute_path, PATH_MAX);
}
- free(expanded_path);
- free(cut_path);
- return next;
+ return absolute_path;
error:
- free(expanded_path);
- free(cut_path);
+ free(absolute_path);
return NULL;
}
projects / lttng-tools.git / blobdiff