1 files changed, 83 insertions, 33 deletions

diff --git a/src/executor.zig b/src/executor.zig
index 02ec159..354e724 100644
--- a/src/executor.zig
+++ b/src/executor.zig
@@ -1,4 +1,5 @@
 const std = @import("std");
+const builtins = @import("builtins.zig");
 
 pub fn runExternalProgram(allocator: std.mem.Allocator, program_path: []const u8, argv: []const []const u8) !void {
     const argv_z = try allocator.allocSentinel(?[*:0]const u8, argv.len, null);
@@ -104,34 +105,49 @@ pub fn runExternalProgramWithRedirect(allocator: std.mem.Allocator, program_path
     }
 }
 
-pub fn runExternalPipeline(allocator: std.mem.Allocator, program1_path: []const u8, argv1: []const []const u8, program2_path: []const u8, argv2: []const []const u8) !void {
-    const argv1_z = try allocator.allocSentinel(?[*:0]const u8, argv1.len, null);
-    defer allocator.free(argv1_z);
-    for (argv1, 0..) |arg, i| {
-        argv1_z[i] = (try allocator.dupeZ(u8, arg)).ptr;
-    }
-    defer {
-        for (argv1_z[0..argv1.len]) |arg_ptr| {
-            if (arg_ptr) |ptr| allocator.free(std.mem.span(ptr));
-        }
-    }
-
-    const argv2_z = try allocator.allocSentinel(?[*:0]const u8, argv2.len, null);
-    defer allocator.free(argv2_z);
-    for (argv2, 0..) |arg, i| {
-        argv2_z[i] = (try allocator.dupeZ(u8, arg)).ptr;
-    }
-    defer {
-        for (argv2_z[0..argv2.len]) |arg_ptr| {
-            if (arg_ptr) |ptr| allocator.free(std.mem.span(ptr));
-        }
+fn runBuiltinInChild(
+    allocator: std.mem.Allocator,
+    cmd_name: []const u8,
+    args: ?[]const u8,
+    stdin_fd: std.posix.fd_t,
+    stdout_fd: std.posix.fd_t,
+) noreturn {
+    // Redirect stdin/stdout to provided fds (already valid)
+    if (stdin_fd != 0) std.posix.dup2(stdin_fd, 0) catch {};
+    if (stdout_fd != 1) std.posix.dup2(stdout_fd, 1) catch {};
+
+    var out_file = std.fs.File{ .handle = 1 };
+    var out_writer = out_file.writerStreaming(&.{});
+    const w = &out_writer.interface;
+
+    if (std.mem.eql(u8, cmd_name, "echo")) {
+        builtins.executeEcho(w, args) catch {};
+    } else if (std.mem.eql(u8, cmd_name, "type")) {
+        builtins.executeType(allocator, w, args) catch {};
+    } else if (std.mem.eql(u8, cmd_name, "pwd")) {
+        builtins.executePwd(allocator, w) catch {};
+    } else if (std.mem.eql(u8, cmd_name, "cd")) {
+        builtins.executeCd(allocator, w, args) catch {};
+    } else if (std.mem.eql(u8, cmd_name, "exit")) {
+        // exit inside pipeline child just exits child
     }
 
-    const program1_path_z = try allocator.dupeZ(u8, program1_path);
-    defer allocator.free(program1_path_z);
-    const program2_path_z = try allocator.dupeZ(u8, program2_path);
-    defer allocator.free(program2_path_z);
+    std.posix.exit(0);
+}
 
+pub fn runPipeline(
+    allocator: std.mem.Allocator,
+    left_path: ?[]const u8,
+    left_builtin: bool,
+    left_name: []const u8,
+    left_args: ?[]const u8,
+    left_argv: ?[]const []const u8,
+    right_path: ?[]const u8,
+    right_builtin: bool,
+    right_name: []const u8,
+    right_args: ?[]const u8,
+    right_argv: ?[]const []const u8,
+) !void {
     const fds = try std.posix.pipe();
 
     const pid1 = try std.posix.fork();
@@ -139,10 +155,27 @@ pub fn runExternalPipeline(allocator: std.mem.Allocator, program1_path: []const
         std.posix.close(fds[0]);
         try std.posix.dup2(fds[1], 1);
         std.posix.close(fds[1]);
-        _ = std.posix.execveZ(program1_path_z, argv1_z, std.c.environ) catch {
-            std.posix.exit(1);
-        };
-        unreachable;
+
+        if (left_builtin) {
+            runBuiltinInChild(allocator, left_name, left_args, 0, 1);
+        } else {
+            const argv1_z = try allocator.allocSentinel(?[*:0]const u8, left_argv.?.len, @as(?[*:0]const u8, null));
+            defer allocator.free(argv1_z);
+            for (left_argv.?, 0..) |arg, i| {
+                argv1_z[i] = (try allocator.dupeZ(u8, arg)).ptr;
+            }
+            defer {
+                for (argv1_z[0..left_argv.?.len]) |arg_ptr| {
+                    if (arg_ptr) |ptr| allocator.free(std.mem.span(ptr));
+                }
+            }
+            const program1_path_z = try allocator.dupeZ(u8, left_path.?);
+            defer allocator.free(program1_path_z);
+            _ = std.posix.execveZ(program1_path_z, argv1_z, std.c.environ) catch {
+                std.posix.exit(1);
+            };
+            unreachable;
+        }
     }
 
     const pid2 = try std.posix.fork();
@@ -150,10 +183,27 @@ pub fn runExternalPipeline(allocator: std.mem.Allocator, program1_path: []const
         std.posix.close(fds[1]);
         try std.posix.dup2(fds[0], 0);
         std.posix.close(fds[0]);
-        _ = std.posix.execveZ(program2_path_z, argv2_z, std.c.environ) catch {
-            std.posix.exit(1);
-        };
-        unreachable;
+
+        if (right_builtin) {
+            runBuiltinInChild(allocator, right_name, right_args, 0, 1);
+        } else {
+            const argv2_z = try allocator.allocSentinel(?[*:0]const u8, right_argv.?.len, @as(?[*:0]const u8, null));
+            defer allocator.free(argv2_z);
+            for (right_argv.?, 0..) |arg, i| {
+                argv2_z[i] = (try allocator.dupeZ(u8, arg)).ptr;
+            }
+            defer {
+                for (argv2_z[0..right_argv.?.len]) |arg_ptr| {
+                    if (arg_ptr) |ptr| allocator.free(std.mem.span(ptr));
+                }
+            }
+            const program2_path_z = try allocator.dupeZ(u8, right_path.?);
+            defer allocator.free(program2_path_z);
+            _ = std.posix.execveZ(program2_path_z, argv2_z, std.c.environ) catch {
+                std.posix.exit(1);
+            };
+            unreachable;
+        }
     }
 
     std.posix.close(fds[0]);