Returns current position in the binary file opened by
|scalar||Number of bytes of the current position from the start of the file|
%FPOSITION has a single unnamed parameter, which saves the current write position in the binary file opened by
%OPEN. This can be used to relocate the
%WRITE directive to that position in the file. For example, if you wanted to change a value in the file later during its use, you could save the position of that value, and then use
%WRITE to write the new value into the file.
%WRITE 0 "Write a dummy value to hold the position"
"... more %WRITE commands"
%FPOSITION file_length "Get current position = file length"
%WRITE [POSITION=file_length_position] file_length