width - set width of file
Width sets to size the width of the current file (see
initio(io)). If size is zero, the width is set to one. The width
is the position (offset within the line) at which a newline is automatically
written by the output functions to wrap the line around. If size is
IBMNOWIDTH (see io(inc)), this wrap-around mechanism is turned off.
Upon opening, the width of a tty is STDWIDTH (see io(inc)); other
files have no width, i.e., the wrap-around mechanism is off.
This function implements the BASIC WIDTH statement.
Error 5 (Illegal function call) is generated if size is negative or is
greater than IBMNOWIDTH.
The Basmark QuickBASIC Programmerís Manual