Closes the file or pipe associated with the file handle, returning true only if IO buffers are successfully flushed and closes the system file descriptor. Closes the currently selected filehandle if the argument is omitted.
You don't have to close FILEHANDLE if you are immediately going to do
open on it, because
open will close it for you. (See
open.) However, an explicit
close on an input file resets the line
), while the implicit close done by
open does not.
If the file handle came from a piped open,
close will additionally
return false if one of the other system calls involved fails, or if the
program exits with non-zero status. (If the only problem was that the
program exited non-zero,
will be set to
.) Closing a pipe
also waits for the process executing on the pipe to complete, in case you
want to look at the output of the pipe afterwards, and
implicitly puts the exit status value of that command into
Prematurely closing the read end of a pipe (i.e. before the process writing to it at the other end has closed it) will result in a SIGPIPE being delivered to the writer. If the other end can't handle that, be sure to read all the data before closing the pipe.
FILEHANDLE may be an expression whose value can be used as an indirect filehandle, usually the real filehandle name.