Program Examples:File Handling:Open Read Write

The following example demonstrates how to open a file with different permissions (Read Only, Write Only, Append), how to read from and write to the file, and how to manipulate the file pointer.

program
	dim pos as long
	dim d1 as double
	dim s1 as string

	'create file for writing
	Open "test.prg" mode = "w" as #1
	print #1, "1.2345"
	close #1

	'append to existing file
	Open "test.prg" mode = "a" as #1
	print #1, PI
	close #1
	'read from file
	Open "test.prg" mode = "r" as #1

	'how many characters in the file?
	print "File contains ";loc(1);" characters"
	s1 = input$(#1)

	'convert from string to double
	d1=val(s1)
	?d1

	'save current file pointer
	pos = tell(#1)
	print "File pointer Position = ";pos
	?input$(#1)

	'rewind file
	seek (#1,pos)
	?input$(#1)
	close #1

end program

See Also

• OPEN
• LOC
• PRINT
• INPUT$
• TELL
• SEEK
• CLOSE