diff --git a/src/system/FileDescriptor.cxx b/src/system/FileDescriptor.cxx
index 51a57512b..1f6bf0808 100644
--- a/src/system/FileDescriptor.cxx
+++ b/src/system/FileDescriptor.cxx
@@ -59,6 +59,13 @@ FileDescriptor::IsValid() const noexcept
 	return IsDefined() && fcntl(fd, F_GETFL) >= 0;
 }
 
+bool
+FileDescriptor::IsRegularFile() const noexcept
+{
+	struct stat st;
+	return IsDefined() && fstat(fd, &st) == 0 && S_ISREG(st.st_mode);
+}
+
 bool
 FileDescriptor::IsPipe() const noexcept
 {
diff --git a/src/system/FileDescriptor.hxx b/src/system/FileDescriptor.hxx
index 11e32caf3..92cdddce6 100644
--- a/src/system/FileDescriptor.hxx
+++ b/src/system/FileDescriptor.hxx
@@ -78,6 +78,12 @@ public:
 	gcc_pure
 	bool IsValid() const noexcept;
 
+	/**
+	 * Ask the kernel whether this is a regular file.
+	 */
+	gcc_pure
+	bool IsRegularFile() const noexcept;
+
 	/**
 	 * Ask the kernel whether this is a pipe.
 	 */