rewrite randomwallpaper in zig

scripts/.gitignore

@@ -0,0 +1 @@
+zig-cache/

scripts/randomwallpaper.c

@@ -1,52 +0,0 @@
-// clang -lX11 -lXinerama randomwallpaper.c -o ~/.local/bin/randomwallpaper
-// this script updates the desktop wallpapers using the nitrogen tool to random
-// wallpapers on all displays.
-#include <X11/Xlib.h>
-#include <X11/extensions/Xinerama.h>
-#include <stdio.h>
-#include <stdlib.h>
-
-void update_wallpapers(Display *d);
-
-int main(int argc, char *argv[]) {
-  Display *d = XOpenDisplay(NULL);
-
-  if (d) {
-    int dummy1, dummy2;
-
-    // check if xinerama is supported and enabled
-    if (XineramaQueryExtension(d, &dummy1, &dummy2) && XineramaIsActive(d)) {
-      update_wallpapers(d);
-    } else {
-      puts("No Xinerama!\n");
-      XCloseDisplay(d);
-      return 1;
-    }
-
-    XCloseDisplay(d);
-    return 0;
-  } else {
-    puts("Couldn't open display!\n");
-    // I return with 0 here, as I don't really wanna see it as an error if this
-    // script is run without an X server running.
-    return 0;
-  }
-}
-
-void update_wallpapers(Display *d) {
-  int heads = 0;
-  XineramaScreenInfo *info = XineramaQueryScreens(d, &heads);
-
-  if (heads > 0) {
-    for (int i = 0; i < heads; i++) {
-      // works as long as the user doesn't have over 999 monitors :P
-      char command[42];
-      sprintf(command, "nitrogen --random --set-scaled --head=%d", i);
-      printf("Setting wallpaper for screen %d with size %dx%d\n", i,
-             info[i].width, info[i].height);
-      system(command);
-    }
-  }
-
-  XFree(info);
-}

scripts/randomwallpaper.zig

@@ -0,0 +1,60 @@
+// zig build-exe -lc -lX11 -lXinerama randomwallpaper.zig && mv randomwallpaper ~/.local/bin
+const std = @import("std");
+const mem = std.mem;
+const c = @cImport({
+    @cInclude("X11/Xlib.h");
+    @cInclude("X11/extensions/Xinerama.h");
+});
+const Display = c.struct__XDisplay;
+
+pub fn main() !void {
+    var alloc = std.heap.GeneralPurposeAllocator(.{}){};
+    const maybe_display = c.XOpenDisplay(null);
+    if (maybe_display) |display| {
+        defer _ = c.XCloseDisplay(display);
+
+        var dummy1: c_int = undefined;
+        var dummy2: c_int = undefined;
+        if (c.XineramaQueryExtension(display, &dummy1, &dummy2) != 0 and c.XineramaIsActive(display) != 0) {
+            try updateWallpapers(display, alloc.allocator());
+        } else {
+            return error.@"No Xinerama!";
+        }
+    }
+}
+
+fn updateWallpapers(display: *Display, alloc: mem.Allocator) !void {
+    const stdout = std.io.getStdOut().writer();
+
+    var heads: c_int = 0;
+    const info = c.XineramaQueryScreens(display, &heads);
+    defer _ = c.XFree(info);
+
+    var children = try alloc.alloc(*std.ChildProcess, @intCast(usize, heads));
+    defer alloc.free(children);
+
+    var i: usize = 0;
+    while (i < heads) {
+        const head = info[i];
+
+        try stdout.print("Setting wallpaper for screen {} with size {}x{}\n", .{ i, head.width, head.height });
+
+        var buf: [10]u8 = undefined;
+
+        const args = [_][]const u8{ "nitrogen", "--random", "--set-scaled", try std.fmt.bufPrint(&buf, "--head={}", .{i}) };
+        var child = try std.ChildProcess.init(&args, alloc);
+        try child.spawn();
+
+        children[i] = child;
+
+        i += 1;
+    }
+
+    for (children) |child| {
+        _ = try child.wait();
+    }
+
+    for (children) |child| {
+        child.deinit();
+    }
+}