Cymblot's Notes

// This is a demo program that shows how to launch
 // an external program and read from it's output.
 program launchprogram;

 // Here we include files that have useful functions
 // and procedures we will need.
 uses
   Classes, SysUtils, Process;

 // This is defining the var "AProcess" as a variable
 // of the type "TProcess"
 // Also now we are adding a TStringList to store the
 // data read from the programs output.
 var
   AProcess: TProcess;
   AStringList: TStringList;

 // This is where our program starts to run
 begin
   // Now we will create the TProcess object, and
   // assign it to the var AProcess.
   AProcess := TProcess.Create(nil);

   // Create the TStringList object.
   AStringList := TStringList.Create;

   // Tell the new AProcess what the command to execute is.
   // Let's use the FreePascal compiler
   AProcess.CommandLine := 'ppc386 -h';

   // We will define an option for when the program
   // is run. This option will make sure that our program
   // does not continue until the program we will launch
   // has stopped running. Also now we will tell it that
   // we want to read the output of the file.
   AProcess.Options := AProcess.Options + [poWaitOnExit, poUsePipes];

   // Now that AProcess knows what the commandline is
   // we will run it.
   AProcess.Execute;

   // This is not reached until ppc386 stops running.

   // Now read the output of the program we just ran
   // into the TStringList.
   AStringList.LoadFromStream(AProcess.Output);

   // Save the output to a file.
   AStringList.SaveToFile('output.txt');

   // Now that the file is saved we can free the
   // TStringList and the TProcess.
   AStringList.Free;
   AProcess.Free;  
 end.