It is currently Tue, 19 Jun 2018 21:02:07 GMT

Author Message
 ksh process substitution - which ksh's support this?

In article <01bced5e$dd619580$>,

ksh does not support process substitution on versions of Unix
without the /dev/fd directory.  Bash uses either /dev/fd or
named pipes to implement process substitution, so bash may provide
process substitution on systems where ksh would not.
``The lyf so short, the craft so long to lerne.'' - Chaucer

Chet Ramey, Case Western Reserve University     Internet: c...@po.CWRU.Edu

 Sun, 30 Apr 2000 03:00:00 GMT   
 ksh process substitution - which ksh's support this?

The Bolsky & Korn book "The KornShell", page 326, under "Possible
Extensions", describes process substitution as being available only
on versions of UNIX that support the /dev/fd directory for naming
open files.  With words like this I would not rely on it being
available for use in a portable script.

  -- Conrad

In article <01bced5e$dd619580$>, "Simon Taylor" <> writes:
|> I have written some ksh scripts that need to be portable across a number
|> of Unixes.
|> To my dismay, I have discovered that the process substitution feature
|> I have in my SCO "Open Server 5" ksh (and in the GNU bash), is not
|> available in the ksh shipped with most of the other Unixes I have
|> access to.
|> Is this just because these machines happen to be a few years old,
|> and the newer ksh simply isn't on them, or is process substitution
|> not supported universally?
|> It is particularly important for me to discover whether this feature
|> is supported in the latest Digital Unix, as it is not present in v4.0
|> of the OS.
|> ie: With a shell that supports process substitution one can, for instance,
|> place a process in the context where a file name is
|> expected. As a trivial example:
|>     wc <(ls)
|> will return the word count of the output of the ls command, as if
|> the output were a file.
|> Regards,
|> --
|> Simon Taylor ( - remove the "X"s to reply)
|> Unisolve Pty Ltd         Melbourne, Australia

Conrad Kimball           | Client Server Tech Svcs, Boeing Information & Supt. | P.O. Box 24346, MS 7M-HC
(425) 865-6410           | Seattle, WA  98124-0346

 Mon, 01 May 2000 03:00:00 GMT   
 ksh process substitution - which ksh's support this?

Process substitution is not supported on all versions of UNIX. This feature
is usually only available on versions of the UNIX operating system that
support the /dev/fd directory for naming open files.

Digital UNIX does not support /dev/fd. Neither do a number of other
UNIX operating systems.


 Tue, 02 May 2000 03:00:00 GMT   
   [ 3 post ] 

Similar Threads

1. ksh process substitution - which ksh's support this?

2. KSH Process doesn't die

3. alias in ksh, argument substitution Question

4. ksh command substitution

5. ksh variable substitution quandry

6. ksh problem with patern substitution

7. ksh command substitution

8. Filename substitution in ksh script

9. ksh substitution problem (help !)

10. ksh: arrays and parameter substitution

Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group.
Designed by ST Software