Remove File Extension from Filename in Zig

Get the filename without its extension using std.fs.path.stem.

This recipe was written using Zig version 0.15.2. If this recipe is outdated, please let me know on X (@sepyke) or Bluesky (@pyk.sh).

When working with file paths in Zig, you often need to extract just the base name of a file without its extension. For example, if you have basic_example.zig, you might want to get basic_example to use as an executable name. Zig’s standard library provides a convenient function for this: std.fs.path.stem.

The std.fs.path.stem function takes a []const u8 (a slice of bytes representing the path) and returns a []const u8 which is the last component of the path without its extension. It handles various cases, including paths with multiple dots in the extension or no extension at all.

Here’s how you can use it:

const std = @import("std");
const fs = std.fs;

pub fn main() !void {
    const filename1 = "basic_example.zig";
    const filename2 = "archive.tar.gz";
    const filename3 = "document";
    const filename4 = ".bashrc"; // Hidden file, stem returns ".bashrc"

    std.debug.print("Original: {s}, Stem: {s}\n", .{ filename1, fs.path.stem(filename1) });
    std.debug.print("Original: {s}, Stem: {s}\n", .{ filename2, fs.path.stem(filename2) });
    std.debug.print("Original: {s}, Stem: {s}\n", .{ filename3, fs.path.stem(filename3) });
    std.debug.print("Original: {s}, Stem: {s}\n", .{ filename4, fs.path.stem(filename4) });
}

Make sure Zig is installed:

$ zig version
0.15.2

Then run it:

$ zig run remove_extension.zig
Original: basic_example.zig, Stem: basic_example
Original: archive.tar.gz, Stem: archive.tar
Original: document, Stem: document
Original: .bashrc, Stem: .bashrc