LibCore: Add utility class for temporary files and directories

Core::TempFile is a RAII type that creates a temporary file or directory
on construction and deletes it on destruction.

Userland/Libraries/LibCore/CMakeLists.txt

@@ -33,6 +33,7 @@ set(SOURCES
     System.cpp
     TCPServer.cpp
     TCPSocket.cpp
+    TempFile.cpp
     Timer.cpp
     UDPServer.cpp
     UDPSocket.cpp

Userland/Libraries/LibCore/TempFile.cpp

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2020-2021, the SerenityOS developers.
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "TempFile.h"
+#include <AK/Random.h>
+#include <AK/Vector.h>
+#include <LibCore/File.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+
+namespace Core {
+
+NonnullOwnPtr<TempFile> TempFile::create(Type type)
+{
+    return adopt_own(*new TempFile(type));
+}
+
+String TempFile::create_temp(Type type)
+{
+    char name_template[] = "/tmp/tmp.XXXXXX";
+    switch (type) {
+    case Type::File: {
+        auto fd = mkstemp(name_template);
+        VERIFY(fd >= 0);
+        close(fd);
+        break;
+    }
+    case Type::Directory: {
+        auto fd = mkdtemp(name_template);
+        VERIFY(fd != nullptr);
+        break;
+    }
+    }
+    return String { name_template };
+}
+
+TempFile::TempFile(Type type)
+    : m_type(type)
+    , m_path(create_temp(type))
+{
+}
+
+TempFile::~TempFile()
+{
+    File::RecursionMode recursion_allowed { File::RecursionMode::Disallowed };
+    if (m_type == Type::Directory)
+        recursion_allowed = File::RecursionMode::Allowed;
+
+    auto rc = File::remove(m_path.characters(), recursion_allowed, false);
+    if (rc.is_error()) {
+        warnln("File::remove failed: {}", rc.error().string_literal());
+    }
+}
+
+}

Userland/Libraries/LibCore/TempFile.h

@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2020-2021, the SerenityOS developers.
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Noncopyable.h>
+#include <AK/String.h>
+
+namespace Core {
+
+class TempFile {
+    AK_MAKE_NONCOPYABLE(TempFile);
+    AK_MAKE_NONMOVABLE(TempFile);
+
+public:
+    enum class Type {
+        File,
+        Directory
+    };
+
+    static NonnullOwnPtr<TempFile> create(Type = Type::File);
+    ~TempFile();
+
+    String path() const { return m_path; }
+
+private:
+    TempFile(Type);
+    static String create_temp(Type);
+
+    Type m_type { Type::File };
+    String m_path;
+};
+
+}