Um... yes, it is Windows-specific.
system() executes a command in the shell.
system("pause") will execute
pause, which does not exist on Linux:
[thomas@singularity ~]$ pause
-bash: pause: command not found
Apart from that little pedantism of mine :oops:, I'd like to remark that blocking a program when it is not necessary is generally not a good idea. When a program is finished with whatever it is doing, then it should exit.
If, for whatever reason, a user wants execution to block, he can still do that from the shell, but it should not be mandatory from the program's side (unless there is a good reason, like waiting for input).