LibCore: Add File::open_file_or_standard_stream()

2 files changed, 17 insertions, 0 deletions

diff --git a/Userland/Libraries/LibCore/Stream.cpp b/Userland/Libraries/LibCore/Stream.cpp
index 5debcb987a..d6462efbbd 100644
--- a/Userland/Libraries/LibCore/Stream.cpp
+++ b/Userland/Libraries/LibCore/Stream.cpp
@@ -153,6 +153,21 @@ bool File::exists(StringView filename)
     return !Core::System::stat(filename).is_error();
 }
 
+ErrorOr<NonnullOwnPtr<File>> File::open_file_or_standard_stream(StringView filename, OpenMode mode)
+{
+    if (!filename.is_empty() && filename != "-"sv)
+        return File::open(filename, mode);
+
+    switch (mode) {
+    case OpenMode::Read:
+        return File::adopt_fd(STDIN_FILENO, mode);
+    case OpenMode::Write:
+        return File::adopt_fd(STDOUT_FILENO, mode);
+    default:
+        VERIFY_NOT_REACHED();
+    }
+}
+
 int File::open_mode_to_options(OpenMode mode)
 {
     int flags = 0;
diff --git a/Userland/Libraries/LibCore/Stream.h b/Userland/Libraries/LibCore/Stream.h
index f21dd8a109..da99054337 100644
--- a/Userland/Libraries/LibCore/Stream.h
+++ b/Userland/Libraries/LibCore/Stream.h
@@ -185,6 +185,8 @@ public:
     static ErrorOr<NonnullOwnPtr<File>> adopt_fd(int fd, OpenMode);
     static bool exists(StringView filename);
 
+    static ErrorOr<NonnullOwnPtr<File>> open_file_or_standard_stream(StringView filename, OpenMode mode);
+
     File(File&& other) { operator=(move(other)); }
 
     File& operator=(File&& other)