June 2002
Beginner
759 pages
80h 42m
English
fileno
fileno filehandle
Returns the file descriptor for a filehandle. (A
file descriptor is a small integer, unlike the filehandle, which
is a symbol.) It returns undef
if the handle is not open. It’s useful for constructing bitmaps
for select and for passing to
certain obscure system calls if syscall is implemented. It’s also useful
for double-checking that the open function gave you the file
descriptor you wanted.