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From: ea08+@andrew.cmu.edu (Eric A. Anderson)
Newsgroups: comp.lang.perl
Subject: Re: read/write pipe
Message-ID: <Mbn9n5G00VQoA9qdhX@andrew.cmu.edu>
Date: 28 Feb 91 06:01:41 GMT
References: <1991Feb25.023300.7836@uvaarpa.Virginia.EDU>
Organization: Carnegie Mellon, Pittsburgh, PA
Lines: 27
In-Reply-To: <1991Feb25.023300.7836@uvaarpa.Virginia.EDU>

marc@athena.mit.edu (Marc Horowitz) writes:
> |> From the keyboard of marc@mit.edu:
> |> :I know this has been mentioned here before, but I don't remember what
> |> :the reasons were.  Why is open(FOO,"|cat|") (a pipe to a program which
> |> :I can read from and write to) not supported?  
> |> 
> |> From the FAQ:
> |> 
> |>     20) How do I open a pipe both to and from a command?
> |> 
> |>      In general, this is a dangerous move because you can find yourself in
> |>      deadlock situation.  It's better to put one end of the pipe to a file.
For whatever reason, I found that open(FOO,'ftp |'); allowed me to do
both writes and reads from FOO.  Is this a mis-feature or something?
Because I find this fundamentaly useful, I want a program which can do
things with ftp sessions.  (Primarily, get all files under some
directory subject to certain constraints.)  The only other way to do
this would be to write a C program containing all of ftp which seems
like overkill.  Am I in risk of a deadlock or something?
          -Eric
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"My life is full of additional complications spinning around until
 it makes my head snap off."
           -Unc. Known.
"You are very smart, shut up."
           -In "The Princess Bride"
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