From 1d6bc6829812a448ac6148e7e86e36dff30d19fb Mon Sep 17 00:00:00 2001
From: Jon Parise <jon@indelible.org>
Date: Wed, 5 Aug 2026 23:07:43 -0400
Subject: [PATCH] lib: remove cutPrefix implementation

We can use std.mem.cutPrefix directly now that we're on Zig 0.16.
---
 src/apprt/gtk/class/application.zig |  7 +++----
 src/cli/new_window.zig              |  5 ++---
 src/lib/main.zig                    |  1 -
 src/lib/string.zig                  | 15 ---------------
 4 files changed, 5 insertions(+), 23 deletions(-)
 delete mode 100644 src/lib/string.zig

diff --git a/src/apprt/gtk/class/application.zig b/src/apprt/gtk/class/application.zig
index 55d7f4055..6c70d0bb3 100644
--- a/src/apprt/gtk/class/application.zig
+++ b/src/apprt/gtk/class/application.zig
@@ -26,7 +26,6 @@ const xev = global.xev;
 const Binding = @import("../../../input.zig").Binding;
 const CoreConfig = configpkg.Config;
 const CoreSurface = @import("../../../Surface.zig");
-const lib = @import("../../../lib/main.zig");
 
 const ext = @import("../ext.zig");
 const key = @import("../key.zig");
@@ -1865,7 +1864,7 @@ pub const Application = extern struct {
                     continue;
                 }
 
-                if (lib.cutPrefix(u8, str, "--command=")) |v| {
+                if (std.mem.cutPrefix(u8, str, "--command=")) |v| {
                     var cmd: configpkg.Command = undefined;
                     cmd.parseCLI(alloc, v) catch |err| {
                         log.warn("unable to parse command: {t}", .{err});
@@ -1874,14 +1873,14 @@ pub const Application = extern struct {
                     command = cmd;
                     continue;
                 }
-                if (lib.cutPrefix(u8, str, "--working-directory=")) |v| {
+                if (std.mem.cutPrefix(u8, str, "--working-directory=")) |v| {
                     working_directory = alloc.dupeZ(u8, std.mem.trim(u8, v, &std.ascii.whitespace)) catch |err| wd: {
                         log.warn("unable to duplicate working directory: {t}", .{err});
                         break :wd null;
                     };
                     continue;
                 }
-                if (lib.cutPrefix(u8, str, "--title=")) |v| {
+                if (std.mem.cutPrefix(u8, str, "--title=")) |v| {
                     title = alloc.dupeZ(u8, std.mem.trim(u8, v, &std.ascii.whitespace)) catch |err| t: {
                         log.warn("unable to duplicate title: {t}", .{err});
                         break :t null;
diff --git a/src/cli/new_window.zig b/src/cli/new_window.zig
index 333cb06c0..bda8bd6cc 100644
--- a/src/cli/new_window.zig
+++ b/src/cli/new_window.zig
@@ -5,7 +5,6 @@ const Action = @import("../cli.zig").ghostty.Action;
 const apprt = @import("../apprt.zig");
 const args = @import("args.zig");
 const diagnostics = @import("diagnostics.zig");
-const lib = @import("../lib/main.zig");
 const homedir = @import("../os/homedir.zig");
 const global = @import("../global.zig");
 
@@ -70,12 +69,12 @@ pub const Options = struct {
         Allocator.Error;
 
     fn checkArg(self: *Options, alloc: Allocator, arg: []const u8) CheckArgError!?[:0]const u8 {
-        if (lib.cutPrefix(u8, arg, "--class=")) |rest| {
+        if (std.mem.cutPrefix(u8, arg, "--class=")) |rest| {
             self.class = try alloc.dupeZ(u8, std.mem.trim(u8, rest, &std.ascii.whitespace));
             return null;
         }
 
-        if (lib.cutPrefix(u8, arg, "--working-directory=")) |rest| {
+        if (std.mem.cutPrefix(u8, arg, "--working-directory=")) |rest| {
             const stripped = std.mem.trim(u8, rest, &std.ascii.whitespace);
             if (std.mem.eql(u8, stripped, "home")) return try alloc.dupeZ(u8, arg);
             if (std.mem.eql(u8, stripped, "inherit")) return try alloc.dupeZ(u8, arg);
diff --git a/src/lib/main.zig b/src/lib/main.zig
index b22b3d987..d9c35927b 100644
--- a/src/lib/main.zig
+++ b/src/lib/main.zig
@@ -13,7 +13,6 @@ pub const Struct = structpkg.Struct;
 pub const structSizedFieldFits = structpkg.sizedFieldFits;
 pub const Target = @import("target.zig").Target;
 pub const TaggedUnion = unionpkg.TaggedUnion;
-pub const cutPrefix = @import("string.zig").cutPrefix;
 
 test {
     std.testing.refAllDecls(@This());
diff --git a/src/lib/string.zig b/src/lib/string.zig
deleted file mode 100644
index 795823c25..000000000
--- a/src/lib/string.zig
+++ /dev/null
@@ -1,15 +0,0 @@
-const std = @import("std");
-
-// This is a copy of std.mem.cutPrefix from 0.16. Once Ghostty has been ported
-// to 0.16 this can be removed.
-
-/// If slice starts with prefix, returns the rest of slice starting at
-/// prefix.len.
-pub fn cutPrefix(comptime T: type, slice: []const T, prefix: []const T) ?[]const T {
-    return if (std.mem.startsWith(T, slice, prefix)) slice[prefix.len..] else null;
-}
-
-test cutPrefix {
-    try std.testing.expectEqualStrings("foo", cutPrefix(u8, "--example=foo", "--example=").?);
-    try std.testing.expectEqual(null, cutPrefix(u8, "--example=foo", "-example="));
-}