These procedures are in structures posix-i/o and posix.
Open-pipe creates a new pipe and returns the two ends as an
input port and an output port.
A file descriptor port (or fd-port)
is a port that reads to or writes from an OS file descriptor.
Fd-ports are returned by open-input-file, open-output-file,
open-file, open-pipe, and other procedures.
Fd-port? returns true if its argument is an fd-port.
Port->fd returns the file descriptor associated with
or #f if port is not an fd-port.
Remap-file-descriptors reassigns file descriptors to ports.
The fd-specs indicate which port is to be mapped to each
file descriptor: the first gets file descriptor 0, the second gets
1, and so forth.
A fd-spec is either a port that reads from or writes to
a file descriptor,
or #f, with #f indicating that the corresponding file
descriptor is not used.
Any open ports not listed are marked `close-on-exec'.
The same port may be moved to multiple new file descriptors.
For example,
(remap-file-descriptors (current-output-port)
#f
(current-input-port))
0 and the
current input port to file descriptor 2.
(dup fd-port) -> fd-port
(dup-switching-mode fd-port) -> fd-port
(dup2 fd-port file-descriptor) -> fd-port
fd-port's file descriptor and return a new port
that uses ports's old file descriptor.
Dup uses the lowest unused file descriptor and dup2 uses the
one provided.
Dup-switching-mode is the same as dup except that the returned
port is an input port if the argument was an output port and vice
versa.
If any existing port uses the file descriptor passed to dup2, that
port is closed.
Close-all-but closes all file descriptors whose associated ports
are not passed to it as arguments.
Close-on-exec? returns true if port will be closed
when a new program is exec'ed.
Set-close-on-exec?! sets port's close-on-exec flag.
These two procedures read and write various options for port.
The options that can be read are append, nonblocking,
read-only, write-only, and read/write.
Only the append and nonblocking can be written.
Port-is-a-terminal? returns true if port has an underlying
file descriptor that is associated with a terminal.
For such ports port-terminal-name returns the name of the
terminal, for all others it returns #f.
Previous: Time | Next: Regular expressions