Legacy Document

Inside Macintosh: Processes

Chapter 2 - Process Manager / Process Manager Reference

Routines / Getting Process Information

GetFrontProcess

Use the GetFrontProcess function to get the process serial number of the front process.

FUNCTION GetFrontProcess (VAR PSN: ProcessSerialNumber): OSErr;

PSN

On output, the process serial number of the process running in the foreground.

DESCRIPTION

The GetFrontProcess function returns, in the PSN parameter, the process serial number of the process running in the foreground. You can use this function to determine if your process or some other process is in the foreground. You can use the process serial number returned in the PSN parameter in other Process Manager routines.

If no process is running in the foreground, GetFrontProcess returns the result code procNotFound.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the GetFrontProcess function are

Trap macro	Selector
_OSDispatch	$0039

RESULT CODES

noErr	0	No error
paramErr	-50	Process serial number is invalid
procNotFound	-600	No process in the foreground