how to kindly stop a pipeline?

[info at mbsoft.biz]

Hi all, i have this pipeline to capture a live video source and a live audio source in an mkv file

gst-launch-1.0.exe -v videotestsrc ! queue ! videoconvert ! mfh264enc bitrate=1024 ! h264parse ! mux. wasapisrc ! queue ! audioconvert ! opusenc ! opusparse ! matroskamux name=mux ! filesink location="E:\test.mkv"

when I press CTRL+C on the console to stop the pipeline I get a corrupted mkv file. Some players do not open it at all, while VLC open it but it's not seekable. Audio and video are ok but probably the matroskamux is not finalizing the file.

How I can exit gst-launch in a kindly way, I mean I want the muxer to complete the file index and exit.

Thank you