Initial commit

.gitignore

@@ -0,0 +1,10 @@
+*
+
+!src/
+
+!.gitignore
+
+!*.lock
+!*.nix
+!*.zig
+!*.zon

build.zig

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+const std = @import("std");
+
+pub fn build(b: *std.Build) void {
+    const target = b.standardTargetOptions(.{});
+    const optimize = b.standardOptimizeOption(.{});
+
+    const exe = b.addExecutable(.{
+        .name = "crash",
+        .root_source_file = b.path("src/main.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+
+    const opts = b.addOptions();
+    opts.addOption(?[]const u8, "fallback_shell", b.option([]const u8, "fallback_shell", "The fallback shell crash will use if it can't read the environment or the variable isn't found"));
+    exe.root_module.addOptions("build_options", opts);
+
+    b.installArtifact(exe);
+
+    const run_cmd = b.addRunArtifact(exe);
+
+    run_cmd.step.dependOn(b.getInstallStep());
+
+    if (b.args) |args| {
+        run_cmd.addArgs(args);
+    }
+
+    const run_step = b.step("run", "Run the program");
+    run_step.dependOn(&run_cmd.step);
+
+    const exe_unit_tests = b.addTest(.{
+        .root_source_file = b.path("src/main.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+
+    const run_exe_unit_tests = b.addRunArtifact(exe_unit_tests);
+
+    const test_step = b.step("test", "Run unit tests");
+    test_step.dependOn(&run_exe_unit_tests.step);
+}

build.zig.zon

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+.{
+    .name = "crash",
+    .version = "0.0.1",
+
+    .minimum_zig_version = "0.12.0",
+
+    .paths = .{
+        "",
+    },
+}

build.zig.zon.nix

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+# generated by zon2nix (https://github.com/nix-community/zon2nix)
+
+{ linkFarm, fetchzip }:
+
+linkFarm "zig-packages" [
+]

flake.lock

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+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1715653339,
+        "narHash": "sha256-7lR9tpVXviSccl07GXI0+ve/natd24HAkuy1sQp0OlI=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "abd6d48f8c77bea7dc51beb2adfa6ed3950d2585",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

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+{
+  description = "Crash";
+
+  nixConfig = {
+    extra-substituters        = "https://cache.garnix.io/";
+    extra-trusted-public-keys = "cache.garnix.io:CTFPyKSLcx5RMJKfLo5EEPUObbA78b0YQ2DTCJXqr9g=";
+  };
+
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+
+  outputs = { nixpkgs, ... }: with nixpkgs.lib; foldl' recursiveUpdate {} (map (system: let
+    pkgs = import nixpkgs { inherit system; };
+  in {
+    devShell.${system} = pkgs.mkShell {
+      packages = with pkgs; [
+        zig_0_12
+        zls
+        zon2nix
+      ];
+    };
+
+    packages.${system} = rec {
+      crash   = pkgs.callPackage ./package.nix {};
+      default = crash;
+    };
+
+  }) [ "x86_64-linux" "aarch64-linux" "riscv64-linux" ]);
+}

package.nix

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+{
+  lib,
+  stdenvNoCC,
+  callPackage,
+
+  zig_0_12,
+  optimize ? "ReleaseFast",
+
+  bash,
+  fallbackShell ? bash,
+}:
+
+stdenvNoCC.mkDerivation {
+  name    = "crash";
+  version = lib.head (lib.strings.match ''.*\.version = "([^"]*)".*'' (lib.readFile ./build.zig.zon));
+
+  src = ./.;
+
+  nativeBuildInputs = [ zig_0_12 ];
+
+  dontConfigure = true;
+  dontInstall   = true;
+
+  preBuild = ''
+    mkdir -p .cache
+    ln -s ${callPackage ./build.zig.zon.nix {}} .cache/p
+  '';
+
+  buildPhase = ''
+    runHook preBuild
+
+    zig build install \
+      --cache-dir $(pwd)/zig-cache \
+      --global-cache-dir $(pwd)/.cache \
+      --prefix $out \
+      -Doptimize=${optimize} \
+      -Dfallback_shell=${lib.getExe fallbackShell}
+
+    runHook postBuild
+  '';
+}

src/main.zig

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+const std = @import("std");
+const fallback_shell = @import("build_options").fallback_shell orelse @compileError("fallback shell was not specified");
+
+pub fn fallback(alloc: std.mem.Allocator) noreturn {
+    const err = std.process.execv(alloc, &[_][]const u8{fallback_shell});
+    std.process.exit(@intCast(@intFromError(err)));
+}
+
+pub fn main() noreturn {
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    const alloc = gpa.allocator();
+
+    const shells = std.posix.getenv("SHELLS") orelse fallback(alloc);
+
+    var it = std.mem.split(u8, shells, ":");
+    while (it.next()) |shell| {
+        var child = std.process.Child.init(&[_][]const u8{shell}, alloc);
+
+        switch (child.spawnAndWait() catch fallback(alloc)) {
+            std.process.Child.Term.Exited => |exit_code| if (exit_code == 0) std.process.exit(0),
+            else => continue,
+        }
+    }
+
+    fallback(alloc);
+}