NAME
	write_bytes - write chars in a given position in a file

SYNOPSIS
	int write_bytes(string filename, int position, string text)

DESCRIPTION
	Write the string 'text' at a given position in a file. If the position
	is negative it is counted backwards from the end of the file.

	If the position is outside the file the nothing is written.

	If the 'text' extends outside the file then the file is extended.

NOTA BENE
	Observe that you overwrite existing data in the file. Not like
	write_file where you only append data at the end.

SEE ALSO
	read_bytes, write_file, read_file