popen()

Charles Hannum CMH117 at psuvm.psu.edu
Mon Mar 5 04:38:57 AEST 1990


In article <21231 at netnews.upenn.edu>, dowding at linc.cis.upenn.edu (John Dowding)
says:
>
>If you write write the temp file to a ram disk, won't this give you
>nearly the same effect as the UNIX pipe?

Close, but *ix pipes are fixed in size.  (The size probably varies from system
to system; I don't know what it is.)  When the pipe is full, the process that
is writing to it is suspended; when it is empty, the process reading from it is
suspended.  This allows a virtually infinite amount of data to pass over the
pipe.  (Just think about "ls -R | find ..." from the root!!)  Writing to a RAM
disk (or *any* disk) under DOS limits the amount of information that can pass
over the pipe.

A side note:  A variant of *ix piping is implemented in OS/2.


Virtually,
- Charles Martin Hannum II       "Klein bottle for sale ... inquire within."
    (That's Charles to you!)     "To life immortal!"
  cmh117 at psuvm.{bitnet,psu.edu}  "No noozzzz izzz netzzzsnoozzzzz..."
  c9h at psuecl.{bitnet,psu.edu}    "Mem'ry, all alone in the moonlight ..."



More information about the Comp.lang.c mailing list