Exec will shell out and run whatever exec called. At least I believe
the correct term is "shell out". Learning Perl says in page 196 that
exec locates the program you called and jumps to it. There is no perl
process anymore. So I guess it's more of an exit Perl and run this
command sort of thing.. So once you do that, Perl is gone. System
however returns you back to Perl. If you want Perl not to wait you can
open a process as a file handle. I haven't tried it however it suggests
this will run Perl and your process in parallel.
Something to try
[EMAIL PROTECTED] wrote:
from what I remember reading and was told as a best practice using exec
/.../..../ was recommended over system. For this reason exec does not
create a child and therefore does not have to wait. the perl process
itself runs the command or program. what are the pros and cons of each?
thanks
Derek B. Smith
OhioHealth IT
UNIX / TSM / EDM Teams
u235sentinel <[EMAIL PROTECTED]>
06/25/2004 11:58 AM
To:
cc: [EMAIL PROTECTED]
Subject: Re: 'system' and parallel execution (was: Re: How to call a perl
script....)
Wiggins d Anconia wrote:
Not exactly, it has been forked and does technically run in parallel,
however 'system' blocks your current process waiting for the child to
finish, so your process is in fact running, but it won't be doing any
work except for waiting for a signal from the child.
There are other ways to have parallel execution,
perldoc perlipc
perldoc -f fork
perldoc -f system
Ok. I'll read those in a minute. After reviewing Learning Perl, I
realize I need to open the process as a file handle for parallel
operations. Called a "piped open". (page 201 Oreilly Learning Perl).
Will get you started. "Network Programming with Perl" by Lincoln Stein
also has excellent chapters on this subject, though lacks a chapter
(probably because of its age) on POE.
Haven't purchased that book yet (it's on my amazon wish list however).
I'll check it out.
Thanks!
