I had such problem. I couldn't and still haven't figured out a way to "unlock" the matrix screen after "cmatrix -l".

It would be nice if a sort of screen lock was implemented.

I haven't figured out a way to "unlock" the matrix screen after "cmatrix -l" too.
BUT
You can do it with a simple code modification，Just find out

case 'L':
    lock = 1;
    break;

in cmatrix.c file.
Then change it to:

case 'L':
    lock = (lock == 0)?1:0;
    break;

Finally, compile and install, just like installing the unmodified version.

After modification, you can switch the lock by entering "L".

When you type cmatrix --help it lists all arguments, containing a description for "-L".
-L: Lock mode (can be closed from another terminal)
But like velade I couldn't find anything stoping the lockmode.

To close it, start another console, type ps -a to get a list of running processes, e.g.

PID   TTY          TIME CMD
16769 pts/7    00:00:01 cmatrix

and stop "cmatrix" using the PID kill <PID> e.g. kill 16769

When you type cmatrix --help it lists all arguments, containing a description for "-L".
-L: Lock mode (can be closed from another terminal)
But like velade I couldn't find anything stoping the lockmode.

To close it, start another console, type ps -a to get a list of running processes, e.g.

PID   TTY          TIME CMD
16769 pts/7    00:00:01 cmatrix

and stop "cmatrix" using the PID kill <PID> e.g. kill 16769

For me killall cmatrix does the thing as well, you do not need to get the PID (be aware that it will terminate all instances of cmatrix)

Documentation is being added. Intended behaviour is that cmatrix -L cannot be terminated from the terminal in which it was run. Use a different terminal or tty to kill it when desired. Generally pkill cmatrix should suffice.

First timer here. What is the file for the man page? Meaning, what needs to be edited to add the -L description when running "man cmatrix"?

Thanks in advance.

First timer here. What is the file for the man page? Meaning, what needs to be edited to add the -L description when running "man cmatrix"?

Thanks in advance.

"man cmatrix" is running the program "man" aka 'manual', which is able to show "a man file" of a programm (when the programer has made "a man file" for his program). "a man file" lists how to work with this programm, showing syntax of variables and and options you can use with the programm. your command is showing the "man file" for the program cmatrix.
to run cmatrix itself just use enter "cmatrix" and press enter, with ctrl + c you can end cmatrix again.
Please, github isn´t the place to ask questions how to run programs on linux in the first place, there are plenty of other places where people are keen to help you learning linux, irc-channels for example. Github has a different purpose...

What do ya'll think about #164 ?