Merge & Transcode
If you have more than one source files that need to be merged into a single output file, the general way is this (no transcoding is necessary if all streams match):
vlc file1.ps file2.ps file3.ps --sout "#gather:std{access=file,mux=ts,dst=all.ts}" --sout-keep
NB that whenever you use sout, your video and audio codecs must "be appropriate" for the mux you use (in this case, ps works with a ts mux, so we're ok).
If you want to write your files out to a mux that doesn't support the current audio or video encoding, or if you are wanting to join streams that do not have matching video/audio, then it is recommended to transcode as well.
Here is an example:
vlc -vvv FILE1.EXT FILE2.EXT FILE3.EXT ETC.ETC --sout-keep --sout=#gather:transcode{vcodec=h264,vb=1024,scale=1,acodec=mp4a,ab=192,channels=6}:standard{access=file,mux=ts,dst=out.mpg} --sout-all
Next edit the path to vlc, input files, and transcode parameters to meet your needs.
Or you can use file appending:
vlc go.ps.1 go.ps.2 go.ps.3 vlc://quit --sout-file-append --sout=file/ps:go.ps
Non Interactive Mode
To do any of this in "non interactive" mode, add -I dummy and also vlc://quit to the end of your list of inputs.