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Setjmp function

In unit System

Save current execution point.

Declaration

pascal
function Setjmp(var S: jmp_buf): LongInt

Description

SetJmp fills S with the necessary data for a jump back to the point where it was called. It returns zero if called in this way. If the function returns nonzero, then it means that a call to LongJmp with S as an argument was made somewhere in the program.

Errors

None.

See also

Example: ex79

pascal
program example79;

{ Program to demonstrate the setjmp, longjmp functions }

procedure dojmp(var env : jmp_buf; value : longint);

begin
  value:=2;
  Writeln ('Going to jump !');
  { This will return to the setjmp call,
    and return value instead of 0 }
  longjmp(env,value);
end;

var env : jmp_buf;

begin
  if setjmp(env)=0 then
    begin
    writeln ('Passed first time.');
    dojmp(env,2);
    end
  else
    writeln ('Passed second time.');
end.

An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.