Copying files from a directory recursively with Zig...

copy.zig

/// Copy a source directory's files and its subdirectories' files to a destination. Will only copy directories and files.
fn copyRecursiveDir(src_dir: fs.Dir, dest_dir: fs.Dir, src_path: []const u8, dest_path: []const u8) anyerror!void {
    var iter = src_dir.iterate();
    while (true) {
        const entry = try iter.next();
        if (entry == null) {
            break;
        } else {
            switch (entry.?.kind) {
                .File => try src_dir.copyFile(entry.?.name, dest_dir, entry.?.name, fs.CopyFileOptions{}),
                .Directory => {
                    // Create destination directory
                    dest_dir.makeDir(entry.?.name) catch |e| {
                        switch (e) {
                            std.os.MakeDirError.PathAlreadyExists => {},
                            else => return e,
                        }
                    };
                    // Open destination directory
                    var dest_entry_dir = try dest_dir.openDir(entry.?.name, fs.Dir.OpenDirOptions{ .access_sub_paths = true, .iterate = true, .no_follow = true });
                    defer dest_entry_dir.close();
                    // Open directory we're copying files from
                    var src_entry_dir = try src_dir.openDir(entry.?.name, fs.Dir.OpenDirOptions{ .access_sub_paths = true, .iterate = true, .no_follow = true });
                    defer src_entry_dir.close();
                    // Begin the recursive descent!
                    try copyRecursiveDir(src_entry_dir, dest_entry_dir, entry.?.name, entry.?.name);
                },
                else => {}, // ¯\_(ツ)_/¯ Don't want any of that stuff, anyway
            }
        }
    }
}