Hello Patricio,

I currently teaching Operative System to students who only know Pascal, so I'd like to know if we can use Unix System calls in pascal programs wirh GPC ? I mean stuff like 'fork()', 'exec()', etc...

You can access any function using the "external", "C", and "asmname" directives:

Procedure fork; external;

means: there is an external Procedure "Fork" (first letter uppercase),

Procedure fork; C;

means: there is an external Procedure "fork" (everything lowercase), and

Procedure fork; asmname 'foO';

means: there is an external Procedure with the funny name "foO" (last letter is uppercase in this example) which can be accessed from Pascal via the name "fork".

Good luck,

Peter