var StdErr: Text;
The StdErr
variable is connected to the standard error file
handle. To report errors, you should prefer
WriteLn (StdErr, 'everything wrong')
over
WriteLn ('everything wrong')
.
StdErr
is a GNU Pascal extension.
program StdErrDemo; var Denominator: Integer; begin ReadLn (Denominator); if Denominator = 0 then WriteLn (StdErr, ParamStr (0), ': division by zero') else WriteLn ('1 / ', Denominator, ' = ', 1 / Denominator) end.