feat(applets): add umount

Author: RossComputerGuy

applets.zig

@@ -5,5 +5,6 @@ pub const chroot = @import("applets/chroot.zig");
 pub const @"false" = @import("applets/false.zig");
 pub const pwd = @import("applets/pwd.zig");
 pub const @"true" = @import("applets/true.zig");
+pub const umount = @import("applets/umount.zig");
 pub const uptime = @import("applets/uptime.zig");
 pub const yes = @import("applets/yes.zig");

applets/umount.zig

@@ -0,0 +1,42 @@
+const builtin = @import("builtin");
+const clap = @import("clap");
+const std = @import("std");
+const ziggybox = @import("ziggybox");
+
+fn umount(path: [*:0]const u8) !void {
+    const r = std.os.linux.umount(path);
+    return switch (std.os.errno(r)) {
+        .SUCCESS => {},
+        .PERM => error.AccessDenied,
+        else => |err| return std.os.unexpectedErrno(err),
+    };
+}
+
+pub fn run(args: *std.process.ArgIterator) !void {
+    const stderr = ziggybox.io.getStdErr();
+
+    const params = comptime clap.parseParamsComptime(
+        \\-h, --help    Display this help and exit.
+        \\<path>        The directory to unmount
+        \\
+    );
+
+    var diag = clap.Diagnostic{};
+    var res = ziggybox.clap.parseEx(clap.Help, &params, comptime .{
+        .path = clap.parsers.string,
+    }, args, .{
+        .allocator = ziggybox.common.allocator,
+        .diagnostic = &diag,
+    }) catch |err| {
+        diag.report(stderr, err) catch {};
+        return err;
+    };
+    defer res.deinit();
+
+    if (res.args.help != 0 or res.positionals.len < 1)
+        return clap.help(stderr, clap.Help, &params, .{});
+
+    const path = try ziggybox.common.allocator.dupeZ(u8, res.positionals[0]);
+    defer ziggybox.common.allocator.free(path);
+    try umount(path);
+}

build.zig

@@ -22,6 +22,7 @@ pub fn build(b: *std.Build) !void {
         "false",
         "pwd",
         "true",
+        "umount",
         "uptime",
         "yes",
     };