initial commit

Signed-off-by: Tim Culverhouse <tim@timculverhouse.com>

.gitignore

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+zig-cache/
+zig-out/

build.zig

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+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 libxev = b.dependency("libxev", .{
+        .optimize = optimize,
+        .target = target,
+    });
+    const ziglyph = b.dependency("ziglyph", .{
+        .optimize = optimize,
+        .target = target,
+    });
+
+    const lib = b.addStaticLibrary(.{
+        .name = "salmon",
+        // 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 = .{ .path = "src/root.zig" },
+        .target = target,
+        .optimize = optimize,
+    });
+
+    // This declares intent for the library to be installed into the standard
+    // location when the user invokes the "install" step (the default step when
+    // running `zig build`).
+    b.installArtifact(lib);
+
+    const exe = b.addExecutable(.{
+        .name = "salmon",
+        .root_source_file = .{ .path = "src/main.zig" },
+        .target = target,
+        .optimize = optimize,
+    });
+    exe.root_module.addImport("ziglyph", ziglyph.module("ziglyph"));
+    exe.root_module.addImport("xev", libxev.module("xev"));
+
+    // 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);
+
+    // Creates a step for unit testing. This only builds the test executable
+    // but does not run it.
+    const lib_unit_tests = b.addTest(.{
+        .root_source_file = .{ .path = "src/root.zig" },
+        .target = target,
+        .optimize = optimize,
+    });
+
+    const run_lib_unit_tests = b.addRunArtifact(lib_unit_tests);
+
+    const exe_unit_tests = b.addTest(.{
+        .root_source_file = .{ .path = "src/main.zig" },
+        .target = target,
+        .optimize = optimize,
+    });
+
+    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_lib_unit_tests.step);
+    test_step.dependOn(&run_exe_unit_tests.step);
+}

build.zig.zon

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+.{
+    .name = "salmon",
+    // 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",
+
+    // This field is optional.
+    // This is currently advisory only; Zig does not yet do anything
+    // with this value.
+    //.minimum_zig_version = "0.11.0",
+
+    .dependencies = .{
+        .libxev = .{
+            .url = "https://github.com/mitchellh/libxev/archive/4e6781895e4e6c477597c8c2713d36cd82b57d07.tar.gz",
+            .hash = "12203f87e00caa6c07c02a748f234a5c0ee2ca5c334ec464e88810d93e7b5495a56f",
+        },
+        .ziglyph = .{
+            .url = "https://codeberg.org/dude_the_builder/ziglyph/archive/main.tar.gz",
+	    .hash = "12208553f3f47e51494e187f4c0e6f6b3844e3993436cad4a0e8c4db4e99645967b5",
+        },
+    },
+
+    .paths = .{
+        // This makes *all* files, recursively, included in this package. It is generally
+        // better to explicitly list the files and directories instead, to insure that
+        // fetching from tarballs, file system paths, and version control all result
+        // in the same contents hash.
+        "",
+        // For example...
+        //"build.zig",
+        //"build.zig.zon",
+        //"src",
+        //"LICENSE",
+        //"README.md",
+    },
+}

src/main.zig

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+const std = @import("std");
+const Tty = @import("tty/Tty.zig");
+
+pub fn main() !void {
+    // 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();
+
+    var tty = try Tty.init();
+    defer tty.deinit();
+
+    try tty.run();
+
+    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());
+}

src/root.zig

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+const std = @import("std");
+const testing = std.testing;
+
+export fn add(a: i32, b: i32) i32 {
+    return a + b;
+}
+
+test "basic add functionality" {
+    try testing.expect(add(3, 7) == 10);
+}

src/tty/Tty.zig

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+const std = @import("std");
+const os = std.os;
+const xev = @import("xev");
+
+const log = std.log.scoped(.tty);
+
+const Tty = @This();
+
+/// the original state of the terminal, prior to calling makeRaw
+termios: os.termios,
+
+/// The file descriptor we are using for I/O
+fd: os.fd_t,
+
+/// Stream attached to our fd
+stream: xev.Stream,
+
+/// event loop
+loop: xev.Loop,
+
+read_buffer: [1024]u8 = undefined,
+
+/// initializes a Tty instance by opening /dev/tty and "making it raw"
+pub fn init() !Tty {
+    // Open our tty
+    const fd = try os.open("/dev/tty", os.system.O.RDWR, 0);
+
+    // Initialize the stream
+    const stream = xev.Stream.initFd(fd);
+
+    // Initialize event loop
+    const loop = try xev.Loop.init(.{});
+
+    // Set the termios of the tty
+    const termios = try makeRaw(fd);
+
+    return Tty{
+        .fd = fd,
+        .stream = stream,
+        .termios = termios,
+        .loop = loop,
+    };
+}
+
+/// release resources associated with the Tty return it to it's original state
+pub fn deinit(self: *Tty) void {
+    os.tcsetattr(self.fd, .FLUSH, self.termios) catch |err| {
+        log.err("couldn't restore terminal: {}", .{err});
+    };
+    os.close(self.fd);
+    self.stream.deinit();
+    self.loop.deinit();
+}
+
+/// read input from the tty
+pub fn run(self: *Tty) !void {
+    var c_stream: xev.Completion = undefined;
+
+    // Initialize our read event
+    self.stream.read(
+        &self.loop,
+        &c_stream,
+        .{ .slice = self.read_buffer[0..] },
+        Tty,
+        self,
+        readCallback,
+    );
+
+    try self.loop.run(.until_done);
+}
+
+fn readCallback(
+    ud: ?*Tty,
+    loop: *xev.Loop,
+    c: *xev.Completion,
+    stream: xev.Stream,
+    buf: xev.ReadBuffer,
+    r: xev.ReadError!usize,
+) xev.CallbackAction {
+    _ = stream; // autofix
+    _ = c; // autofix
+    _ = loop; // autofix
+    const tty = ud.?;
+    _ = tty; // autofix
+    const n = r catch |err| {
+        // Log the error and shutdown
+        log.err("read error: {}", .{err});
+        return .disarm;
+    };
+    log.info("{s}\r", .{buf.slice[0..n]});
+    return .rearm;
+}
+
+/// makeRaw enters the raw state for the terminal.
+pub fn makeRaw(fd: os.fd_t) !os.termios {
+    const state = try os.tcgetattr(fd);
+    var raw = state;
+    // see termios(3)
+    raw.iflag &= ~@as(
+        os.tcflag_t,
+        os.system.IGNBRK |
+            os.system.BRKINT |
+            os.system.PARMRK |
+            os.system.ISTRIP |
+            os.system.INLCR |
+            os.system.IGNCR |
+            os.system.ICRNL |
+            os.system.IXON,
+    );
+    raw.oflag &= ~@as(os.tcflag_t, os.system.OPOST);
+    raw.lflag &= ~@as(
+        os.tcflag_t,
+        os.system.ECHO |
+            os.system.ECHONL |
+            os.system.ICANON |
+            os.system.ISIG |
+            os.system.IEXTEN,
+    );
+    raw.cflag &= ~@as(
+        os.tcflag_t,
+        os.system.CSIZE |
+            os.system.PARENB,
+    );
+    raw.cflag |= @as(
+        os.tcflag_t,
+        os.system.CS8,
+    );
+    raw.cc[os.system.V.MIN] = 1;
+    raw.cc[os.system.V.TIME] = 0;
+    try os.tcsetattr(fd, .FLUSH, raw);
+    return state;
+}

src/tty/main.zig

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+const std = @import("std");
+const os = std.os;
+
+pub const Tty = @import("Tty.zig");