• Places
    • Home
    • Graphs
    • Prefixes
  • Admin
    • Users
    • Settings
    • Plugins
    • Statistics
  • CPACK
    • Home
    • List packs
    • Submit pack
  • Repository
    • Load local file
    • Load from HTTP
    • Load from library
    • Remove triples
    • Clear repository
  • Query
    • YASGUI SPARQL Editor
    • Simple Form
    • SWISH Prolog shell
  • Help
    • Documentation
    • Tutorial
    • Roadmap
    • HTTP Services
  • Login

17 library(unix): Unix specific operations
All Application Manual Name SummaryHelp

  • Documentation
    • Reference manual
    • Packages
      • SWI-Prolog C-library
        • library(unix): 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
Availability::- use_module(library(unix)).(can be autoloaded)
Source[det]pipe(-InSream, -OutStream)
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)
        ).
ClioPatria (version V3.1.1-51-ga0b30a5)