feat(util): add ScopedFd RAII utility for file descriptors

Signed-off-by: Austin Horstman <khaneliman12@gmail.com>

include/util/scoped_fd.hpp

@@ -0,0 +1,54 @@
+#pragma once
+
+#include <unistd.h>
+
+namespace waybar::util {
+
+class ScopedFd {
+ public:
+  explicit ScopedFd(int fd = -1) : fd_(fd) {}
+  ~ScopedFd() {
+    if (fd_ != -1) {
+      close(fd_);
+    }
+  }
+
+  // ScopedFd is non-copyable
+  ScopedFd(const ScopedFd&) = delete;
+  ScopedFd& operator=(const ScopedFd&) = delete;
+
+  // ScopedFd is moveable
+  ScopedFd(ScopedFd&& other) noexcept : fd_(other.fd_) { other.fd_ = -1; }
+  ScopedFd& operator=(ScopedFd&& other) noexcept {
+    if (this != &other) {
+      if (fd_ != -1) {
+        close(fd_);
+      }
+      fd_ = other.fd_;
+      other.fd_ = -1;
+    }
+    return *this;
+  }
+
+  int get() const { return fd_; }
+
+  operator int() const { return fd_; }
+
+  void reset(int fd = -1) {
+    if (fd_ != -1) {
+      close(fd_);
+    }
+    fd_ = fd;
+  }
+
+  int release() {
+    int fd = fd_;
+    fd_ = -1;
+    return fd;
+  }
+
+ private:
+  int fd_;
+};
+
+}  // namespace waybar::util