fifo2(n) fifo2(n)

NAME
       fifo2 - Create and manipulate pipe fifo channels

SYNOPSIS
       package require TTccll

       package require mmeemmcchhaann

       ffiiffoo22


DESCRIPTION
       The command described here is only available in a not-yet released ver-
       sion of the package. Use the CVS to get the sources.

       ffiiffoo22  creates two stream-oriented in-memory channels and returns their
              handles  as  a  two-element list. There is no restriction on the
              ultimate size of the channels, they will always grow as much  as
              is necessary to accomodate the data written into them.

              In contrast to the channels generated by ffiiffoo a pair of channels
              created here is connected internally in such  a  way  that  data
              written  into  one  channel can be read from the other. All data
              written into them is read in the same  order.  This  also  means
              that the two channels of the pair are not seekable.

              The channels created here can be transfered between interpreters
              in the same thread and between threads. As both channels in  the
              pair  can be transfered independently they can be used to create
              a bidirectional connection between two interpreters.

       Memory channels created by ffiiffoo22 provide two  read-only  options  which
       can be queried via the standard ffccoonnffiigguurree command. These are

       -rlength
              The value of this option is the number of bytes currently avail-
              able for reading from the channel.

       -wlength
              The value of this option is the number of bytes currently  writ-
              ten into the channel.

       Note  that  the two lengths are switched for the channels of a pair. In
       other words, the number of bytes written for one of the channels is the
       number of bytes readable from the other end.

       As  the  channels  generated by ffiiffoo22 grow as necessary they are always
       writable. This means that a writable ffiilleeeevveenntt-handler will  fire  con-
       tinuously.

       The  channels  are  also readable if they contain more than zero bytes.
       Under this conditions a readable ffiilleeeevveenntt-handler will  fire  continu-
       ously.

SEE ALSO
       fifo, memchan, null

KKEEYYWWOORRDDSS
       channel, fifo, i/o, in-memory channel, memchan, stream

COPYRIGHT
       Copyright (c) 1996-2003 Andreas Kupries 



Memory channels                       2.2                             fifo2(n)