execution of command inside for loop fails

[kaka_2]

Hello Monks

i am writing a perl script to do small automation for my application. which require applcation's command to be run. first i use it in sub and it works well but next when i use inside the for loop it does not. can someone tell me what wrong i am doing.

 sub ReadPolicies { # based on the below command it reads values in ar
+ray

my ($type) = @_;
my @Policies = `/opt/OV/bin/opctemplate -l | grep -i $type | awk '{pri
+nt \$2}'`;
return (@Policies);

}

#MAIN
My @FailoverPolicies = &ReadPolicies(DBSPI);

For (my $i=0; $i < @FailoverPolicies; i++) {
Print "/opt/OV/bin/opctemplate -e" . " " . $FailoverPolicies[$i], "\n"
+;
$output= `/opt/OV/bin/opctemplate –e $FailoverPolicies[$i]`; # here i 
+expect this command read each value from the array and take action, -
+e to enable

}

-KAKA-

[hdb]

If you add use strict; use warnings; at the beginning of your script, Perl will tell you what you are doing wrong.

UPDATE: I cannot test this but I guess you need a chomp. Here is how I would write it:

use strict;
use warnings;

sub ReadPolicies {
    my $type = shift;
    my @Policies = `/opt/OV/bin/opctemplate -l | grep -i $type | awk '
+{print \$2}'`;
    return @Policies;
}

for( ReadPolicies( "DBSPI" ) ){
    chomp; # not sure this is required....
    my $cmd = "/opt/OV/bin/opctemplate -e $_";
    print "$cmd\n";
    my $output= `$cmd`;
    print "$output\n";
}

[kaka_2]

Thank You. adding strict and warnings was very helpful.

[kaka_2]

Here is my updated code

 sub ReadPolicies { # based on the below command it reads values in ar
+ray

my ($type) = @_;
my @Policies = `/opt/OV/bin/opctemplate -l | grep -i $type | awk '{pri
+nt \$2}'`;
return (@Policies);

}

#MAIN
My @FailoverPolicies = &ReadPolicies(DBSPI);

For (my $i=0; $i < @FailoverPolicies; $i++) {
my $cmd "/opt/OV/bin/opctemplate -e" . " " . "$FailoverPolicies[$i]";
my $output= `$cmd`; # here i expect this command read each value from 
+the array and take action, -e to enable

}

and this works fine but the problem i face is that i see so many <defunct> process on system and i think it is because first command is not completed and second also start and so one and one point this hangs.

What can i do to ensure 2nd command executes only when first is completed in the loop.

Thank You.

-KAKA-

[jethro]

I see "i++" instead of "$i++". I would suggest using foreach loop in such cases, no need for a loop variable.

UPDATE: Please next time also add a description of how it is not working. You'll get much better answers that way

[kaka_2]

Sorry. it was typo but i have $i++ in my script.

[moritz]

That doesn't seem to be your only typo. Please use copy&paste to copy your actual code.

In programming, every single character can be the difference between a program working and failing. It's not efficient at all to work with something that vaguely looks like your real code, but gets some details wrong.