diff --git a/src/system/Open.cxx b/src/system/Open.cxx
index ab8008c38..e7bea24a2 100644
--- a/src/system/Open.cxx
+++ b/src/system/Open.cxx
@@ -43,6 +43,30 @@ OpenReadOnly(const char *path)
 	return fd;
 }
 
+UniqueFileDescriptor
+OpenWriteOnly(const char *path, int flags)
+{
+	UniqueFileDescriptor fd;
+	if (!fd.Open(path, O_WRONLY|flags))
+		throw FormatErrno("Failed to open '%s'", path);
+
+	return fd;
+}
+
+#ifndef _WIN32
+
+UniqueFileDescriptor
+OpenDirectory(const char *path, int flags)
+{
+	UniqueFileDescriptor fd;
+	if (!fd.Open(path, O_DIRECTORY|O_RDONLY|flags))
+		throw FormatErrno("Failed to open '%s'", path);
+
+	return fd;
+}
+
+#endif
+
 #ifdef __linux__
 
 UniqueFileDescriptor
@@ -75,6 +99,16 @@ OpenReadOnly(FileDescriptor directory, const char *name, int flags)
 	return fd;
 }
 
+UniqueFileDescriptor
+OpenWriteOnly(FileDescriptor directory, const char *name, int flags)
+{
+	UniqueFileDescriptor fd;
+	if (!fd.Open(directory, name, O_WRONLY|flags))
+		throw FormatErrno("Failed to open '%s'", name);
+
+	return fd;
+}
+
 UniqueFileDescriptor
 OpenDirectory(FileDescriptor directory, const char *name, int flags)
 {
diff --git a/src/system/Open.hxx b/src/system/Open.hxx
index af4e50bf5..8607a7975 100644
--- a/src/system/Open.hxx
+++ b/src/system/Open.hxx
@@ -36,6 +36,17 @@ class UniqueFileDescriptor;
 UniqueFileDescriptor
 OpenReadOnly(const char *path);
 
+UniqueFileDescriptor
+OpenWriteOnly(const char *path, int flags=0);
+
+
+#ifndef _WIN32
+
+UniqueFileDescriptor
+OpenDirectory(const char *name, int flags=0);
+
+#endif
+
 #ifdef __linux__
 
 UniqueFileDescriptor
@@ -47,6 +58,9 @@ OpenPath(FileDescriptor directory, const char *name, int flags=0);
 UniqueFileDescriptor
 OpenReadOnly(FileDescriptor directory, const char *name, int flags=0);
 
+UniqueFileDescriptor
+OpenWriteOnly(FileDescriptor directory, const char *name, int flags=0);
+
 UniqueFileDescriptor
 OpenDirectory(FileDescriptor directory, const char *name, int flags=0);