return NULL;
}
+static
+char *expand_double_slashes_dot_and_dotdot(char *path)
+{
+ size_t expanded_path_len, path_len;
+ const char *curr_char, *path_last_char, *next_slash, *prev_slash;
+
+ path_len = strlen(path);
+ path_last_char = &path[path_len];
+
+ if (path_len == 0) {
+ path = NULL;
+ goto error;
+ }
+
+ expanded_path_len = 0;
+
+ /* We iterate over the provided path to expand the "//", "../" and "./" */
+ for (curr_char = path; curr_char <= path_last_char; curr_char = next_slash + 1) {
+ /* Find the next forward slash. */
+ size_t curr_token_len;
+
+ if (curr_char == path_last_char) {
+ expanded_path_len++;
+ break;
+ }
+
+ next_slash = memchr(curr_char, '/', path_last_char - curr_char);
+ if (next_slash == NULL) {
+ /* Reached the end of the provided path. */
+ next_slash = path_last_char;
+ }
+
+ /* Compute how long is the previous token. */
+ curr_token_len = next_slash - curr_char;
+ switch(curr_token_len) {
+ case 0:
+ /*
+ * The pointer has not move meaning that curr_char is
+ * pointing to a slash. It that case there is no token
+ * to copy, so continue the iteration to find the next
+ * token
+ */
+ continue;
+ case 1:
+ /*
+ * The pointer moved 1 character. Check if that
+ * character is a dot ('.'), if it is: omit it, else
+ * copy the token to the normalized path.
+ */
+ if (curr_char[0] == '.') {
+ continue;
+ }
+ break;
+ case 2:
+ /*
+ * The pointer moved 2 characters. Check if these
+ * characters are double dots ('..'). If that is the
+ * case, we need to remove the last token of the
+ * normalized path.
+ */
+ if (curr_char[0] == '.' && curr_char[1] == '.') {
+ /*
+ * Find the previous path component by
+ * using the memrchr function to find the
+ * previous forward slash and substract that
+ * len to the resulting path.
+ */
+ prev_slash = lttng_memrchr(path, '/', expanded_path_len);
+ /*
+ * If prev_slash is NULL, we reached the
+ * beginning of the path. We can't go back any
+ * further.
+ */
+ if (prev_slash != NULL) {
+ expanded_path_len = prev_slash - path;
+ }
+ continue;
+ }
+ break;
+ default:
+ break;
+ }
+
+ /*
+ * Copy the current token which is neither a '.' nor a '..'.
+ */
+ path[expanded_path_len++] = '/';
+ memcpy(&path[expanded_path_len], curr_char, curr_token_len);
+ expanded_path_len += curr_token_len;
+ }
+
+ if (expanded_path_len == 0) {
+ path[expanded_path_len++] = '/';
+ }
+
+ path[expanded_path_len] = '\0';
+
+error:
+ return path;
+}
+
/*
* Make a full resolution of the given path even if it doesn't exist.
* This function uses the utils_partial_realpath function to resolve
* the responsibility of the caller to free this memory.
*/
LTTNG_HIDDEN
-char *utils_expand_path(const char *path)
+char *_utils_expand_path(const char *path, bool keep_symlink)
{
- char *next, *previous, *slash, *start_path, *absolute_path = NULL;
+ char *absolute_path = NULL;
char *last_token;
int is_dot, is_dotdot;
goto error;
}
- /*
- * 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 {
+ if (path[0] == '/') {
strncpy(absolute_path, path, PATH_MAX);
- }
-
- /* Resolve partially our path */
- absolute_path = utils_partial_realpath(absolute_path,
- absolute_path, PATH_MAX);
-
- /* As long as we find '/./' in the working_path string */
- while ((next = strstr(absolute_path, "/./"))) {
-
- /* We prepare the start_path not containing it */
- start_path = lttng_strndup(absolute_path, next - absolute_path);
- if (!start_path) {
- PERROR("lttng_strndup");
+ } else {
+ /*
+ * This is a relative path. We need to get the present working
+ * directory and start the path walk from there.
+ */
+ char current_working_dir[PATH_MAX];
+ char *cwd_ret;
+ cwd_ret = getcwd(current_working_dir, sizeof(current_working_dir));
+ if (!cwd_ret) {
+ absolute_path = NULL;
goto error;
}
- /* And we concatenate it with the part after this string */
- snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 2);
-
- free(start_path);
+ /*
+ * Get the number of character in the CWD and allocate an array
+ * to can hold it and the path provided by the caller.
+ */
+ snprintf(absolute_path, PATH_MAX, "%s/%s", current_working_dir, path);
}
- /* 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;
- }
-
- /* Then we prepare the start_path not containing it */
- start_path = lttng_strndup(absolute_path, previous - absolute_path);
- if (!start_path) {
- PERROR("lttng_strndup");
- goto error;
- }
-
- /* 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 */
+ if (keep_symlink) {
+ /* Resolve partially our path */
absolute_path = utils_partial_realpath(absolute_path,
absolute_path, PATH_MAX);
}
+ absolute_path = expand_double_slashes_dot_and_dotdot(absolute_path);
+ if (!absolute_path) {
+ goto error;
+ }
+
/* Identify the last token */
last_token = strrchr(absolute_path, '/');
free(absolute_path);
return NULL;
}
+LTTNG_HIDDEN
+char *utils_expand_path(const char *path)
+{
+ return _utils_expand_path(path, true);
+}
+LTTNG_HIDDEN
+char *utils_expand_path_keep_symlink(const char *path)
+{
+ return _utils_expand_path(path, false);
+}
/*
* Create a pipe in dst.
*/
projects / lttng-tools.git / commitdiff
