3 files changed, 146 insertions(+), 0 deletions(-)

A README.md
A build.zig
A src/main.zig

@@ 1,32 @@
+# Zig-shell
+
+My best attempt at making a shell in zig.
+
+Only cd is implemented for now.
+
+Based on https://zig-by-example.github.io/shell.html
+
+# Installation and usage
+
+```
+git clone https://git.sr.ht/~tieong/zig-shell
+cd zig-shell
+zig build
+./zig-out/bin/zig-shell
+```
+
+# TODO
+
+- Autocompletion
+
+- Understand shortcuts such as ctrl+l to clear the screen, see the resources section.
+
+- Fix the stderr of externals commands such as rm, right now the errors are not displayed
+
+# Resources
+
+- https://viewsourcecode.org/snaptoken/kilo/02.enteringRawMode.html
+
+- https://ziglang.org/documentation/master/std/#stdmem
+
+- https://github.com/Hejsil/zig-clap/tree/09d8261653cbdc61d926fbbdf8bd805abc3f5e5e

@@ 1,33 @@
+const std = @import("std");
+
+pub fn build(b: *std.build.Builder) void {
+    // Standard target options allows the person running `zig build` to choose
+    // what target to build for. Here we do not override the defaults, which
+    // means any target is allowed, and the default is native. Other options
+    // for restricting supported target set are available.
+    const target = b.standardTargetOptions(.{});
+
+    // Standard release options allow the person running `zig build` to select
+    // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall.
+    const mode = b.standardReleaseOptions();
+
+    const exe = b.addExecutable("zig-shell", "src/main.zig");
+    exe.setTarget(target);
+    exe.setBuildMode(mode);
+    exe.install();
+
+    const run_cmd = exe.run();
+    run_cmd.step.dependOn(b.getInstallStep());
+    if (b.args) |args| {
+        run_cmd.addArgs(args);
+    }
+
+    const run_step = b.step("run", "Run the app");
+    run_step.dependOn(&run_cmd.step);
+
+    const exe_tests = b.addTest("src/main.zig");
+    exe_tests.setBuildMode(mode);
+
+    const test_step = b.step("test", "Run unit tests");
+    test_step.dependOn(&exe_tests.step);
+}

@@ 1,81 @@
+const std = @import("std");
+const os = std.os;
+const mem = std.mem;
+
+const stdout = std.io.getStdOut().writer();
+const stdin = std.io.getStdIn().reader();
+
+const ArrayList = std.ArrayList;
+const test_allocator = std.testing.allocator;
+
+const shell_primitives = enum {
+    cd,
+};
+
+const Error = error{
+    CommandFailed,
+    UnknownCommand,
+    EmptyCommand,
+};
+
+fn changeDir(directory: []const u8) !void {
+    try std.os.chdir(directory);
+}
+
+fn autoComplete() !void {}
+
+fn getArgs(line: []const u8) ![]const []const u8 {
+    var args = ArrayList([]const u8).init(test_allocator);
+    defer args.deinit();
+
+    var tokens = mem.split(u8, line, " ");
+
+    while (tokens.next()) |string| {
+        try args.append(string);
+    }
+
+    return args.toOwnedSlice();
+}
+
+fn evalArgs(args: []const []const u8) !void {
+    if (args.len == 0) {
+        return;
+    } else if (mem.eql(u8, args[0], "clear")) {
+        try stdout.writeAll("\x1b[1;1H\x1b[2J");
+    } else if (mem.eql(u8, args[0], "cd") and args.len > 1) {
+        try changeDir(args[1]);
+    } else if (mem.eql(u8, args[0], "exit")) {
+        os.exit(0);
+    } else {
+        const res = std.ChildProcess.exec(.{ .allocator = std.heap.page_allocator, .argv = args }) catch |err| {
+            switch (err) {
+                error.FileNotFound => return Error.UnknownCommand,
+                else => {
+                    try stdout.writeAll(@errorName(err));
+                    return Error.CommandFailed;
+                },
+            }
+        };
+        try stdout.writeAll(res.stdout);
+    }
+}
+
+fn mainLoop() !void {
+    var buf: [512]u8 = undefined;
+    // TODO Implement raw mode to enable ^L to clear the terminal
+    while (true) {
+        try stdout.print("> ", .{});
+        var line = try stdin.readUntilDelimiter(&buf, '\n');
+        const actual_line = mem.trim(u8, line, "\r\n ");
+        const args = try getArgs(actual_line);
+        evalArgs(args) catch |err| {
+            if (err == Error.UnknownCommand) {
+                _ = try stdout.write("Command not found!\n");
+            }
+        };
+    }
+}
+
+pub fn main() anyerror!void {
+    try mainLoop();
+}