Trying to get prompt

using a readline style library too.

.gitignore

@@ -1,2 +1,4 @@
 *.out
 bin/
+.zig-cache
+zig-out

Makefile

@@ -1,18 +1,15 @@
 LIBRARIES = -lreadline
 RELEASE_ARGS = -DRELEASEBUILD
 SOURCES = ./msh.c
-OUTPUT_DIR = ./bin
+OUTPUT_DIR = ./zig-out/bin
 OUTPUT_BIN = ${OUTPUT_DIR}/PROG
 OUTPUT = -o ${OUTPUT_BIN}
 
 build: output_dir
-	gcc -Wall -std=gnu99 ${RELEASE_ARGS} ${SOURCES} ${OUTPUT:PROG=mash} ${LIBRARIES}
+	zig build install --release=fast
 
 debug: output_dir
-	gcc -Wall -std=gnu99 -g ${SOURCES} ${OUTPUT:PROG=mash} ${LIBRARIES}
+	zig build
-
-output_dir:
-	mkdir -p ${OUTPUT_DIR}
 
 install:
 	mv ${OUTPUT_BIN:PROG=mash} /usr/sbin/blah

build.zig

@@ -0,0 +1,81 @@
+const std = @import("std");
+
+// Although this function looks imperative, note that its job is to
+// declaratively construct a build graph that will be executed by an external
+// runner.
+pub fn build(b: *std.Build) void {
+    // Standard target options allows the person running `zig build` to choose
+    // what target to build for. Here we do not override the defaults, which
+    // means any target is allowed, and the default is native. Other options
+    // for restricting supported target set are available.
+    const target = b.standardTargetOptions(.{});
+
+    // Standard optimization options allow the person running `zig build` to select
+    // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not
+    // set a preferred release mode, allowing the user to decide how to optimize.
+    const optimize = b.standardOptimizeOption(.{});
+
+    const linenoise = b.dependency("linenoize", .{
+        .target = target,
+        .optimize = optimize,
+    }).module("linenoise");
+
+    // We will also create a module for our other entry point, 'main.zig'.
+    const exe_mod = b.createModule(.{
+        // `root_source_file` is the Zig "entry point" of the module. If a module
+        // only contains e.g. external object files, you can make this `null`.
+        // In this case the main source file is merely a path, however, in more
+        // complicated build scripts, this could be a generated file.
+        .root_source_file = b.path("src/main.zig"),
+        .imports = &.{.{ .name = "linenoise", .module = linenoise }},
+        .target = target,
+        .optimize = optimize,
+    });
+
+    // This creates another `std.Build.Step.Compile`, but this one builds an executable
+    // rather than a static library.
+    const exe = b.addExecutable(.{
+        .name = "math_shell",
+        .root_module = exe_mod,
+    });
+
+    // This declares intent for the executable to be installed into the
+    // standard location when the user invokes the "install" step (the default
+    // step when running `zig build`).
+    b.installArtifact(exe);
+
+    // This *creates* a Run step in the build graph, to be executed when another
+    // step is evaluated that depends on it. The next line below will establish
+    // such a dependency.
+    const run_cmd = b.addRunArtifact(exe);
+
+    // By making the run step depend on the install step, it will be run from the
+    // installation directory rather than directly from within the cache directory.
+    // This is not necessary, however, if the application depends on other installed
+    // files, this ensures they will be present and in the expected location.
+    run_cmd.step.dependOn(b.getInstallStep());
+
+    // This allows the user to pass arguments to the application in the build
+    // command itself, like this: `zig build run -- arg1 arg2 etc`
+    if (b.args) |args| {
+        run_cmd.addArgs(args);
+    }
+
+    // This creates a build step. It will be visible in the `zig build --help` menu,
+    // and can be selected like this: `zig build run`
+    // This will evaluate the `run` step rather than the default, which is "install".
+    const run_step = b.step("run", "Run the app");
+    run_step.dependOn(&run_cmd.step);
+
+    const exe_unit_tests = b.addTest(.{
+        .root_module = exe_mod,
+    });
+
+    const run_exe_unit_tests = b.addRunArtifact(exe_unit_tests);
+
+    // Similar to creating the run step earlier, this exposes a `test` step to
+    // the `zig build --help` menu, providing a way for the user to request
+    // running the unit tests.
+    const test_step = b.step("test", "Run unit tests");
+    test_step.dependOn(&run_exe_unit_tests.step);
+}

build.zig.zon

@@ -0,0 +1,52 @@
+.{
+    // This is the default name used by packages depending on this one. For
+    // example, when a user runs `zig fetch --save <url>`, this field is used
+    // as the key in the `dependencies` table. Although the user can choose a
+    // different name, most users will stick with this provided value.
+    //
+    // It is redundant to include "zig" in this name because it is already
+    // within the Zig package namespace.
+    .name = .math_shell,
+
+    // This is a [Semantic Version](https://semver.org/).
+    // In a future version of Zig it will be used for package deduplication.
+    .version = "0.0.0",
+
+    // Together with name, this represents a globally unique package
+    // identifier. This field is generated by the Zig toolchain when the
+    // package is first created, and then *never changes*. This allows
+    // unambiguous detection of one package being an updated version of
+    // another.
+    //
+    // When forking a Zig project, this id should be regenerated (delete the
+    // field and run `zig build`) if the upstream project is still maintained.
+    // Otherwise, the fork is *hostile*, attempting to take control over the
+    // original project's identity. Thus it is recommended to leave the comment
+    // on the following line intact, so that it shows up in code reviews that
+    // modify the field.
+    .fingerprint = 0x62a0107bbe8924ff, // Changing this has security and trust implications.
+
+    // Tracks the earliest Zig version that the package considers to be a
+    // supported use case.
+    .minimum_zig_version = "0.14.0",
+
+    // This field is optional.
+    // Each dependency must either provide a `url` and `hash`, or a `path`.
+    // `zig build --fetch` can be used to fetch all dependencies of a package, recursively.
+    // Once all dependencies are fetched, `zig build` no longer requires
+    // internet connectivity.
+    .dependencies = .{
+        .linenoize = .{
+            .url = "git+https://github.com/joachimschmidt557/linenoize?ref=v0.1.0#8bf767663382624bd676b05829fa8d3975a05d88",
+            .hash = "linenoize-0.1.0-J7HK8IfXAABxH-V4Bp2Q0G7P-nrOmq9g8LuQAoX3SjDy",
+        },
+    },
+    .paths = .{
+        "build.zig",
+        "build.zig.zon",
+        "src",
+        // For example...
+        //"LICENSE",
+        //"README.md",
+    },
+}

msh.c

@@ -251,7 +251,6 @@ char *getPrompt() {
 		printf("Error forking\n");
 	} else { // Parent process
 		close(input.read);
-    close(input.write);
 		close(output.write);
 
 		outputFileD = fdopen(output.read, "r");

msh.h

@@ -1,4 +0,0 @@
-int builtinExit(char **args);
-int builtinAuthor(char **args);
-int builtinCD(char **dir);
-int builtinNMN(char **args);

src/get_prompt.bash

@@ -0,0 +1,7 @@
+ver=$(bash --version | head -n 1 | awk '{print $4}' | grep -o "\.\..")
+check_ver=$(echo -e "${ver}\n4.3" | sort -V | head -n 1)
+if [[ "${ver}" == "${check_ver}" ]]; then
+  echo "[${USER}@${HOSTNAME} ${PWD##*/}]$ "
+else
+  echo "${PS1@P}"
+fi

src/main.zig

@@ -0,0 +1,98 @@
+const std = @import("std");
+const Linenoise = @import("linenoise").Linenoise;
+
+fn clear() !void {
+    const stdout = std.io.getStdOut().writer();
+    try stdout.print("\u{001b}[H\u{001b}[J", .{});
+}
+const Pipe = packed struct {
+    const fd_t = std.posix.fd_t;
+    read: fd_t,
+    write: fd_t,
+};
+
+fn pipe() !Pipe {
+    return @bitCast(try std.posix.pipe());
+}
+
+fn getPrompt() ![]const u8 {
+    const p = try pipe();
+
+    const close = std.posix.close;
+    const dup2 = std.posix.dup2;
+    const STDIN_FILENO = std.posix.STDIN_FILENO;
+    const STDOUT_FILENO = std.posix.STDOUT_FILENO;
+    const STDERR_FILENO = std.posix.STDERR_FILENO;
+    const script = @embedFile("./get_prompt.bash");
+
+    if (std.posix.fork()) |pid| {
+        if (pid == 0) {
+            close(p.read);
+
+            try dup2(p.write, STDOUT_FILENO);
+            close(STDIN_FILENO);
+            close(STDERR_FILENO); // Do not print errors to the screen
+
+            // Command-line arguments (must include program name as first argument)
+            // const args = [_:null]?[*:0]const u8{ "bash", "-i", "-c", script, null };
+            var args = [_:null]?[*:0]const u8{ "bash", "-i", "-c", script, null };
+            try std.posix.execvpeZ("bash", &args, std.c.environ);
+
+            // std.posix.execvpeZ("bash", @as([*:null]const ?[*:0]const u8, &args[0]), std.os.environ);
+            _ = std.posix.execvpeZ("bash", @as([*:null]const ?[*:0]const u8, &args[0]), std.os.environ);
+            // kill the child
+            std.process.exit(0);
+        } else {}
+        return "";
+    } else |err| {
+        return err;
+    }
+}
+
+pub fn main() !void {
+    try clear();
+
+    const allocator = std.heap.page_allocator;
+    var ln = Linenoise.init(allocator);
+    defer ln.deinit();
+
+    _ = try getPrompt();
+
+    while (try ln.linenoise("hello> ")) |input| {
+        defer allocator.free(input);
+        std.debug.print("input: {s}\n", .{input});
+        try ln.history.add(input);
+    }
+
+    // // Prints to stderr (it's a shortcut based on `std.io.getStdErr()`)
+    // std.debug.print("All your {s} are belong to us.\n", .{"codebase"});
+
+    // // stdout is for the actual output of your application, for example if you
+    // // are implementing gzip, then only the compressed bytes should be sent to
+    // // stdout, not any debugging messages.
+    // const stdout_file = std.io.getStdOut().writer();
+    // var bw = std.io.bufferedWriter(stdout_file);
+    // const stdout = bw.writer();
+
+    // try stdout.print("Run `zig build test` to run the tests.\n", .{});
+
+    // try bw.flush(); // Don't forget to flush!
+}
+
+test "simple test" {
+    var list = std.ArrayList(i32).init(std.testing.allocator);
+    defer list.deinit(); // Try commenting this out and see if zig detects the memory leak!
+    try list.append(42);
+    try std.testing.expectEqual(@as(i32, 42), list.pop());
+}
+
+test "fuzz example" {
+    const Context = struct {
+        fn testOne(context: @This(), input: []const u8) anyerror!void {
+            _ = context;
+            // Try passing `--fuzz` to `zig build test` and see if it manages to fail this test case!
+            try std.testing.expect(!std.mem.eql(u8, "canyoufindme", input));
+        }
+    };
+    try std.testing.fuzz(Context{}, Context.testOne, .{});
+}