@node unlock, io
@findex unlock
@subheading Syntax

@example
#include <io.h>

int unlock(int fd, long offset, long length);
@end example

@subheading Description
Unlocks a region previously locked by @code{lock}.

@xref{lock}.

@subheading Return Value
Zero if successful, nonzero if not.


@subheading Portability

@portability !ansi, !posix