Hi guys, I've discovered that the cat command can join files in Linux. However, I had a small problem. When I try to concatenate parts of a movies named as the following
The uploader of these files set a password for these files, so when I join it in Windows by a joining-file software, I know that I have to enter the password to be able to join them. In Linux, however, I use the cat command
and the final file cannot be played. I think that because I haven't entered the password for joining. So, my question is that is there any methods to join password-protected files in Linux.

there is no such thing as a generic password protected file. that's totally down to the kind of file you're referring to.

Maybe I do not explain clearly my question. I mean that, when the uploader split the files into ABC.avi.__a..., he/she used a program called FFSJ which allows him/her to set a password when splitting the movie into many parts. When joining these parts, I have to know the password in order to join them. In Windows, I use this FFSJ software to join these parts, but in Linux, I don't know any methods to do the same thing.

in general you need the same software to protect and handle later a file. So most likely you would need ffsj to join parts and decode it. probably you can use wine to run this program under linux.

no, you explained it fine. Those files created with some hokey windows app in some unknown and non standard way. There is no mention to the source code nor the license it's released under on the website...

I find out that FFSJ can be installed on Linux with Wine and it works fine. Problem solved. Thanks