thanks for that sample code. I added a little more to try it with multiple child processes. It turns out that the nice carries over to all the child processes on my solaris box.
> -----Original Message----- > From: Jonathan E. Paton [mailto:[EMAIL PROTECTED]] > Sent: Tuesday, March 19, 2002 1:28 PM > To: [EMAIL PROTECTED] > Subject: Re: nice, perl, fork and exec > > > > If I run a perl script with nice, (in Unix > > it reprioritizes the process), and fork in > > perl and run an exec "command" with the > > child, does the nice priority apply to > > he child process also? and what about the > > exec of the child process does it apply > > there too? > > IIRC... > > Whenever you launch a child process, the child > has the same permissions as the parent had/has. > > For fork: > > I know, that on Linux for the first time through > the child shares the same timeslot with its > parent. I don't know, however, if that also > applies to the next timeslots - it may be > platform dependent. > > For exec: > > The process information (e.g. timeslot) applies > as it did to the original. > > > > > While we are on the subject, what about system() > > and/or `` (backticks)? > > system/`` creates a child process which Perl > carefully arranges behind the scenes. Perl blocks > on these anyway whilst waiting for data, so you > are unlikely to need to worry too much here. > > > man nice didn't give me any information about > > child processes. > > man evil ;-) > > > This is probably a perlcore developer type > > question huh? > > Not really, Perl implements stuff pretty much > the way the C people do - who use libraries > that show much of Unix's nasty guts in the APIs > etc. > > > Or more likely a unix admin type question? > > Definately. > > > If so anyone know of a good unix mail list? > > Have a wonder around: > > www.linuxdoc.org > > you may find something on this topic, if all > else fails look for the glibc book (older book) > which has the C interface for fork/exec etc. > > Of course, you can check (and I recommend you > do :) that I'm correct by doing something like: > > #!/usr/bin/perl -w > exec 'perl test.pl SLEEP' unless @ARGV; > sleep 120; # Sleep 2 minutes > > and starting it off with nice, then use ps. > > Jonathan Paton > > __________________________________________________ > Do You Yahoo!? > Everything you'll ever need on one web page > from News and Sport to Email and Music Charts > http://uk.my.yahoo.com > > -- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > ---------------------------------------------------------------------------- -------------------- The views and opinions expressed in this email message are the sender's own, and do not necessarily represent the views and opinions of Summit Systems Inc. -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
