2 files changed, 16 insertions, 9 deletions
diff --git a/src/fs.zig b/src/fs.zig
index 8ae9d8e..49041e2 100644
--- a/src/fs.zig
+++ b/src/fs.zig
@@ -100,7 +100,7 @@ pub fn join_path_and_filename(alloc: std.mem.Allocator, paths: []const []const u
     return try std.fs.path.join(alloc, paths2);
 }
 
-pub fn get_mtime(alloc: std.mem.Allocator, path: []const u8) ![]const u8 {
+pub fn get_mtime(alloc: std.mem.Allocator, path: []const u8) !std.os.linux.timespec {
     const attr = try alloc.create(std.os.linux.Stat);
     defer alloc.destroy(attr);
 
@@ -108,16 +108,22 @@ pub fn get_mtime(alloc: std.mem.Allocator, path: []const u8) ![]const u8 {
     defer alloc.free(pathZ);
 
     // use stat to get mtime
-    _ = std.os.linux.stat(pathZ, attr);
+    const rc = std.os.linux.stat(pathZ, attr);
+    if (rc < 0) return error.UnknownStatError;
 
-    // use libc strftime to format time string
-    const mtime = attr.mtime();
-    const mtime_str = try alloc.alloc(u8, 512);
+    return attr.mtime();
+}
+
+// use libc strftime to format time string
+pub fn format_mtime(alloc: std.mem.Allocator, mtime: std.os.linux.timespec, fmt: [*c]const u8) ![]const u8 {
+    const mtime_str = try alloc.alloc(u8, std.os.linux.PATH_MAX);
+    const tm = c.localtime(&mtime.sec);
     const n = c.strftime(
         mtime_str.ptr,
         mtime_str.len,
-        "%F",
-        c.localtime(&mtime.sec),
+        fmt,
+        tm,
     );
+    if (n < 0) return error.UnknownStrftimeError;
     return try alloc.realloc(mtime_str, n);
 }
diff --git a/src/gen.zig b/src/gen.zig
index dbfb1ba..6d2f124 100644
--- a/src/gen.zig
+++ b/src/gen.zig
@@ -110,7 +110,8 @@ fn genSite(ctx: *Context) !void {
 // build a single html file
 fn build(allocator: std.mem.Allocator, w: std.io.AnyWriter, page_name: []const u8, srcpath: []const u8) !void {
     const mtime = try fs.get_mtime(allocator, srcpath);
-    defer allocator.free(mtime);
+    const mtime_str = try fs.format_mtime(allocator, mtime, "%F");
+    defer allocator.free(mtime_str);
 
     // HEAD
     try w.print(
@@ -178,7 +179,7 @@ fn build(allocator: std.mem.Allocator, w: std.io.AnyWriter, page_name: []const u
         .LICENSE_NAME = Context.params.LICENSE_NAME,
         .LICENSE_URL = Context.params.LICENSE_URL,
         .LICENSE_YEAR = Context.params.LICENSE_YEAR,
-        .MTIME = mtime,
+        .MTIME = mtime_str,
         .PATH = srcpath,
         .PUBLIC_INBOX = Context.params.PUBLIC_INBOX,
         .SOURCE_URL = Context.params.SOURCE_URL,