feat(macos): add package manager info (homebrew)

src/macos/packages.zig

@@ -0,0 +1,36 @@
+const std = @import("std");
+const utils = @import("utils.zig");
+
+pub fn getPackagesInfo(allocator: std.mem.Allocator) ![]const u8 {
+    var packages_info = std.ArrayList(u8).init(allocator);
+    defer packages_info.deinit();
+
+    const homebrew_packages = try countHomebrewPackages();
+    const homebrew_casks = try countHomebrewCasks();
+
+    var buffer: [10]u8 = undefined;
+    var fbs = std.io.fixedBufferStream(&buffer);
+
+    if (homebrew_packages > 0) {
+        try std.fmt.formatInt(homebrew_packages, 10, .lower, .{}, fbs.writer());
+        try packages_info.appendSlice("brew: ");
+        try packages_info.appendSlice(fbs.getWritten());
+    }
+
+    if (homebrew_casks > 0) {
+        fbs.reset();
+        try std.fmt.formatInt(homebrew_casks, 10, .lower, .{}, fbs.writer());
+        try packages_info.appendSlice(" brew-cask: ");
+        try packages_info.appendSlice(fbs.getWritten());
+    }
+
+    return try allocator.dupe(u8, packages_info.items);
+}
+
+fn countHomebrewPackages() !usize {
+    return try utils.countEntries("/opt/homebrew/Cellar");
+}
+
+fn countHomebrewCasks() !usize {
+    return try utils.countEntries("/opt/homebrew/Caskroom");
+}