scanner: Ensure parent directory exists for output file

Signed-off-by: ComixHe <heyuming@deepin.org>

src/scanner.c

@@ -37,6 +37,8 @@
 #include <getopt.h>
 #include <limits.h>
 #include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
 
 #if HAVE_LIBXML
 #include <libxml/parser.h>
@@ -2031,6 +2033,87 @@ free_protocol(struct protocol *protocol)
 	free_description(protocol->description);
 }
 
+static int
+ensure_parent_dir(const char *path, mode_t mode) {
+	if (path == NULL || *path == '\0') {
+		errno = EINVAL;
+		return -1;
+	}
+
+	char path_copy[PATH_MAX];
+	size_t len = strlen(path);
+	if (len >= sizeof(path_copy)) {
+		errno = ENAMETOOLONG;
+		return -1;
+	}
+	memcpy(path_copy, path, len + 1);
+
+	/* Remove trailing slashes unless it's the root */
+	while (len > 1 && path_copy[len - 1] == '/')
+		path_copy[--len] = '\0';
+
+	char *last_slash = strrchr(path_copy, '/');
+	if (last_slash == NULL || last_slash == path_copy)
+		return 0;
+	*last_slash = '\0';
+
+	/* start walking directories */
+        int dfd = AT_FDCWD;
+        int ret = 0;
+	char *p = path_copy;
+
+	if (*p == '/') {
+		dfd = open("/", O_RDONLY | O_DIRECTORY);
+		if (dfd < 0)
+			return -1;
+
+		while (*p == '/')
+			++p;
+	}
+
+	while (*p != '\0') {
+		char *slash = strchr(p, '/');
+		if (slash != NULL)
+			*slash = '\0';
+
+		int new_dfd = openat(dfd, p, O_RDONLY | O_DIRECTORY);
+		if (new_dfd < 0) {
+			if (errno == ENOENT) {
+                          	if (mkdirat(dfd, p, mode) < 0 && errno != EEXIST) {
+					ret = -1;
+					goto cleanup;
+				}
+
+				new_dfd = openat(dfd, p, O_RDONLY | O_DIRECTORY);
+                                if (new_dfd < 0) {
+					ret = -1;
+					goto cleanup;
+				}
+                        } else {
+				ret = -1;
+				goto cleanup;
+			}
+		}
+
+		if (dfd != AT_FDCWD)
+			close(dfd);
+		dfd = new_dfd;
+
+		if (slash == NULL)
+			break;
+
+		*slash = '/';
+		p = slash + 1;
+		while (*p == '/')
+			++p;
+        }
+
+cleanup:
+	if (dfd != AT_FDCWD)
+		close(dfd);
+	return ret;
+}
+
 int main(int argc, char *argv[])
 {
 	struct parse_context ctx;
@@ -2120,8 +2203,17 @@ int main(int argc, char *argv[])
 			fprintf(stderr, "Could not open input file: %s\n",
 				strerror(errno));
 			exit(EXIT_FAILURE);
-		}
-		if (freopen(argv[2], "w", stdout) == NULL) {
+                }
+
+                /* ensure the parent directory of the output file exists */
+                if (ensure_parent_dir(argv[2], 0755) < 0) {
+			fprintf(stderr, "Could not create parent directory of output file: %s\n",
+				strerror(errno));
+			fclose(input);
+			exit(EXIT_FAILURE);
+                }
+
+                if (freopen(argv[2], "w", stdout) == NULL) {
 			fprintf(stderr, "Could not open output file: %s\n",
 				strerror(errno));
 			fclose(input);