diff --git a/src/bash.zig b/src/bash.zig
index 25f40b5..56971b1 100644
--- a/src/bash.zig
+++ b/src/bash.zig
@@ -8,7 +8,7 @@ const lib = @import("lib.zig");
 
 pub fn main(init: std.process.Init) !void {
     const arena: std.mem.Allocator = init.arena.allocator();
-    const io = init.io;
+    // const io = init.io;
 
     var environ_map = try lib.fixupEnvironMap(arena, init.environ_map, .user);
     defer environ_map.deinit();
@@ -16,7 +16,7 @@ pub fn main(init: std.process.Init) !void {
     var argv: std.ArrayList([]const u8) = .empty;
     defer argv.deinit(arena);
 
-    try argv.append(arena, options.bash);
+    try argv.append(arena, "bash");
 
     var it = try init.minimal.args.iterateAllocator(arena);
     defer it.deinit();
@@ -28,10 +28,12 @@ pub fn main(init: std.process.Init) !void {
 
     try lib.switchToUser();
 
-    const err = std.process.replace(io, .{
-        .argv = argv.items,
-        .environ_map = &environ_map,
-    });
+    try lib.exec(init.gpa, options.bash, argv, &environ_map);
 
-    std.debug.print("unable to execute: {t}\n", .{err});
+    // const err = std.process.replace(io, .{
+    //     .argv = argv.items,
+    //     .environ_map = &environ_map,
+    // });
+
+    // std.debug.print("unable to execute: {t}\n", .{err});
 }
diff --git a/src/lib.zig b/src/lib.zig
index a9cee89..9f1daa0 100644
--- a/src/lib.zig
+++ b/src/lib.zig
@@ -3,10 +3,12 @@
 
 const std = @import("std");
 
+pub const exec = @import("lib/process.zig").exec;
 pub const fixupEnvironMap = @import("lib/env.zig").fixupEnvironMap;
 pub const switchToUser = @import("lib/switchtouser.zig").switchToUser;
 
 test {
     _ = @import("lib/env.zig");
+    _ = @import("lib/process.zig");
     _ = @import("lib/switchtouser.zig");
 }
diff --git a/src/lib/passwd.zig b/src/lib/passwd.zig
new file mode 100644
index 0000000..9bdfaf5
--- /dev/null
+++ b/src/lib/passwd.zig
@@ -0,0 +1,58 @@
+// SPDX-FileCopyrightText: © 2023 Jeffrey C. Ollie
+// SPDX-License-Identifier: MIT
+
+const std = @import("std");
+const options = @import("options");
+
+pub fn getUserUid(
+    io: std.Io,
+    name: []const u8,
+) !?u32 {
+    var passwd_file = try std.Io.Dir.openFileAbsolute(io, "/etc/passwd", .{ .mode = .read_only });
+    defer passwd_file.close(io);
+
+    // room for 2 paths (home directory and shell) plus a generous amount for the rest
+    var passwd_buf: [1024 + std.fs.max_path_bytes * 2]u8 = undefined;
+    var passwd_file_reader = passwd_file.reader(io, &passwd_buf);
+    const reader = &passwd_file_reader.interface;
+
+    while (true) {
+        const line = reader.takeDelimiter('\n') catch |err| switch (err) {
+            error.ReadFailed => return error.ReadFailed,
+            error.StreamTooLong => return error.StreamTooLong,
+        } orelse return null;
+        var it = std.mem.splitScalar(u8, line, ':');
+        const username = it.next() orelse continue;
+        if (!std.mem.eql(u8, username, name)) continue;
+        _ = it.next(); // skip password field
+        const uid_str = it.next() orelse return error.MissingUID;
+        return try std.fmt.parseUnsigned(u32, uid_str, 10);
+    }
+}
+
+pub fn getUserGid(
+    io: std.Io,
+    name: []const u8,
+) !?u32 {
+    var passwd_file = try std.Io.Dir.openFileAbsolute(io, "/etc/passwd", .{ .mode = .read_only });
+    defer passwd_file.close(io);
+
+    // room for 2 paths (home directory and shell) plus a generous amount for the rest
+    var passwd_buf: [1024 + std.fs.max_path_bytes * 2]u8 = undefined;
+    var passwd_file_reader = passwd_file.reader(io, &passwd_buf);
+    const reader = &passwd_file_reader.interface;
+
+    while (true) {
+        const line = reader.takeDelimiter('\n') catch |err| switch (err) {
+            error.ReadFailed => return error.ReadFailed,
+            error.StreamTooLong => return error.StreamTooLong,
+        } orelse return null;
+        var it = std.mem.splitScalar(u8, line, ':');
+        const username = it.next() orelse continue;
+        if (!std.mem.eql(u8, username, name)) continue;
+        _ = it.next(); // skip password field
+        _ = it.next(); // skip uid field
+        const gid_str = it.next() orelse return error.MissingGID;
+        return try std.fmt.parseUnsigned(u32, gid_str, 10);
+    }
+}
diff --git a/src/lib/process.zig b/src/lib/process.zig
new file mode 100644
index 0000000..5dc461c
--- /dev/null
+++ b/src/lib/process.zig
@@ -0,0 +1,26 @@
+// SPDX-FileCopyrightText: © 2023 Jeffrey C. Ollie
+// SPDX-License-Identifier: MIT
+
+const std = @import("std");
+const options = @import("options");
+
+pub fn exec(gpa: std.mem.Allocator, path: []const u8, argv: []const []const u8, map: *const std.process.Environ.Map) !void {
+    var arena: std.heap.ArenaAllocator = .init(gpa);
+    defer arena.deinit();
+    const alloc = arena.allocator();
+
+    const path0 = try alloc.dupeZ(u8, path);
+
+    const argv0 = try alloc.allocSentinel(?[*:0]const u8, argv.len, null);
+    for (argv, 0..) |arg, i| argv0[i] = (try alloc.dupeZ(u8, arg)).ptr;
+
+    const block = try map.createPosixBlock(alloc, .{ .zig_progress_fd = -1 });
+
+    const rc = std.os.linux.execve(
+        path0.ptr,
+        argv0.ptr,
+        block,
+    );
+
+    return std.posix.unexpectedErrno(rc);
+}