/usr/local/lib/swipl/library/ext/clib/unix.pl
All Application Manual Name SummaryHelp

  • ext
    • clib
      • socket.pl -- Network socket (TCP and UDP) library
      • uid.pl -- User and group management on Unix systems
      • unix.pl -- Unix specific operations
        • fork/1
        • fork_exec/1
        • exec/1
        • wait/2
        • kill/2
        • pipe/2
        • dup/2
        • detach_IO/1
        • detach_IO/0
        • prctl/1
        • sysconf/1
      • syslog.pl -- Unix syslog interface
      • memfile.pl
      • time.pl -- Time and alarm library
      • uri.pl -- Process URIs
      • uuid.pl -- Universally Unique Identifier (UUID) Library
      • sha.pl -- SHA secure hashes
      • process.pl -- Create processes and redirect I/O
      • filesex.pl -- Extended operations on files
      • hash_stream.pl -- Maintain a hash on a stream
      • md5.pl -- MD5 hashes
      • rlimit.pl
      • mallocinfo.pl -- Memory allocation details
      • streampool.pl -- Input multiplexing
      • udp_broadcast.pl -- A UDP broadcast proxy
 pipe(-InSream, -OutStream) is det
Create a communication-pipe. This is normally used to make a child communicate to its parent. After pipe/2, the process is cloned and, depending on the desired direction, both processes close the end of the pipe they do not use. Then they use the remaining stream to communicate. Here is a simple example:
:- use_module(library(unix)).

fork_demo(Result) :-
        pipe(Read, Write),
        fork(Pid),
        (   Pid == child
        ->  close(Read),
            format(Write, '~q.~n',
                   [hello(world)]),
            flush_output(Write),
            halt
        ;   close(Write),
            read(Read, Result),
            close(Read)
        ).