4.7.4. Unix Inter Process Communication - Simple Techniques

• shell redirection
• shellouts: ($EDITOR, $PAGER)

• pipes (named and unamed)
  • implicit synchronisation
  • unidirectional

• tempfiles
  • open -> unlink -> fork

• Signals
  • sent to a process
  • SIGUSR1 and SIGUSR2 can be used for applications
  • conventions for daemons:
    • SIGHUP: reinitalize
    • SIGTERM: gracefull shutdown
    • SIGKILL: unblockable, will kill process
    • SIGINT: ctrl-c