PICK% [(JobID] or
PICK% (JobID, action)
This function can be used to perform various acts.
The first syntax is the more common and will bring the specified Job (by reference to its QDOS Job id or its Job Number as specified by JOBS) to the top of the pile under the Pointer Environment, making all of its windows appear on screen as if it had been Picked from the Qpac 2 file menu.
If JobID is -1 or omitted, then the Job which contains this command, ie the current job, is brought to the top of the pile. This variant is therefore similar to TOP_WINDOW.
If JobID is -2, then the next Job in the Job Table (see NXJOB) is brought to the top of the pile - this is therefore similar to pressing <CTRL><C>.
The second variant is more complex and depends upon the values of JobID and action.
- If JobID refers to an existing Job and action is -4, then the screen is frozen - this is equivalent to pressing <CTRL><F5>.
- If JobID equals -3 and action is an existing QDOS channel number (see CHANNELS) or SuperBASIC channel number then that particular channel is unfrozen, allowing input from / output to that channel provided that the Job which owns that channel is at the top of the pile or can use background screen access under PEX.
- If JobID equals -4 and action is an existing QDOS channel number (see CHANNELS) or SuperBASIC channel number then that particular channel is frozen again and any attempt by a program to access that channel will (unless that program is not buried) cause that program to halt temporarily.
The values returned by PICK% are normally zero if the function is successful. Otherwise errors are returned as follows:
- -1 : Job is In Use (although we are not certain when this will be reported).
- -2 : Job does not exist.
- -6 : Specified QDOS channel number does not exist.