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Re: parallel functions

by kcott (Canon)
on Nov 07, 2012 at 21:58 UTC ( #1002757=note: print w/replies, xml ) Need Help??


in reply to parallel functions

G'day micmac,

If you add use warnings;, you'll see that the exec is not being run at all:

$ pm_child_execs.pl in test2 Can't exec "1": No such file or directory at ./pm_child_execs.pl line +13. in test1 Can't exec "1": No such file or directory at ./pm_child_execs.pl line +13. in test2 Can't exec "1": No such file or directory at ./pm_child_execs.pl line +13.

What's actually happening is that $cmd->() is being run then exec is trying to use the return value ("1" from say) as its argument.

So, the first child runs test1() then, because there's no exec, it runs test2() on the second iteration. The second child runs test2() (also with no exec). That's test1() once and test2() twice.

Changing

exec $cmd->();

to

#exec $cmd->(); $cmd->(); last;

you'll get the desired output:

$ pm_child_execs.pl in test2 in test1

I'll leave you to decide if that's also the desired functionality.

-- Ken

Replies are listed 'Best First'.
Re^2: parallel functions
by micmac (Acolyte) on Nov 07, 2012 at 22:11 UTC
    Good explanation, thanks Ken.

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