codecrafters submit [skip ci]

1 files changed, 59 insertions, 0 deletions

diff --git a/src/executor.zig b/src/executor.zig
index cdddb4f..02ec159 100644
--- a/src/executor.zig
+++ b/src/executor.zig
@@ -103,3 +103,62 @@ pub fn runExternalProgramWithRedirect(allocator: std.mem.Allocator, program_path
         _ = std.posix.waitpid(pid, 0);
     }
 }
+
+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));
+        }
+    }
+
+    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);
+
+    const fds = try std.posix.pipe();
+
+    const pid1 = try std.posix.fork();
+    if (pid1 == 0) {
+        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;
+    }
+
+    const pid2 = try std.posix.fork();
+    if (pid2 == 0) {
+        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;
+    }
+
+    std.posix.close(fds[0]);
+    std.posix.close(fds[1]);
+
+    _ = std.posix.waitpid(pid1, 0);
+    _ = std.posix.waitpid(pid2, 0);
+}