[fpc-pascal] CTRL-Break and asynchronous exec
Marco van de Voort
marcov at stack.nl
Fri Apr 10 16:48:54 CEST 2009
In our previous episode, Jürgen Hestermann said:
> I am trying to port some console programs to Free-Pascal(they use the
> CRT unit and originaly where written for Turbo-Pascal then they were
> ported to Virtual-Pascal). I use "MODE OBJFPC". Now I am stumbling over
> some problems:
> 1.) I check for keyboard input with the READKEY function. How can I
> avoid that the key STRG-C stops the program? I want to use this key for
> the Copy-to-clipboard function. In the manual "CHECKBREAK" is mentioned
> but there it also says that it's not used (and setting it to FALSE
> doesn't change anything).
Don't know if there is a generic function to do this. However in such cases
it is easiest to look how FPC's biggest console app (the textmode IDE) does
> 2.) Is there a (Free-Pascal) standard function to execute other programs
> synchronously AND asynchronously (so that there is no need to change
> this code for different platforms)?
Synchronously: TProcess or ExecuteProcess
> Or do I have to use WinAPI functions
> like CREATEPROCESS for that? Virtual-Pascal had an EXECFLAGS variable
> which controlled the behaviour of the EXEC function. Does something
> similar exist in Free-Pascal?
Do not use the dos.exec function. It has argument and path length problems
(due to shortstrings), use the executeprocess function(s) instead. They are
And in general, have a look at tprocess:
and the fcl-process examples (hopefully) installed with your release.
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