return a variable from command line execution to perl

sss has asked for the wisdom of the Perl Monks concerning the following question:

Hi, i need some help regarding command line execution from perl. I have a .cmd script which sets the property to a key. So i execute this script with two arguments. The first arg is a key in a properties value and the second arg is the varibale which gets the value of the property and gets assigned. Now, i need to call this script from a perl script and gets the value of a property to get assigned to a variable. Using system is not helping. system ("call set_prop.cmd db.server.name dbserver") Please help how can i get this working.

Comment on return a variable from command line execution to perl

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Re: return a variable from command line execution to perl by Corion (Patriarch) on Aug 15, 2014 at 13:42 UTC
So, how does the child process communicate the "property" and the "key" to the calling process? If that `cmd` only sets the value in the environment, you will have to call that `.cmd` in a way very similar (but different to) Get default login environment. Maybe the following works as another wrapper `.cmd` file: `@echo off cd /d %~dp0 call set_prop.cmd db.server.name dbserver set` [download] You would then use the output of that intermediate `.cmd` file as follows from Perl: `my @output= qx(get_property_values.cmd); chomp @output; print "Got output [$_]" for @output;` [download] Alternatively, see perlipc.	[reply] [d/l] [select]
Re^2: return a variable from command line execution to perl by sss (Initiate) on Aug 15, 2014 at 15:04 UTC
Thank you Corion. I figured out a different way. use backticks and then echo the variable at the end. $dbserv=`call set_prop.cmd db.server.name dbserver & echo %dbserver%` This worked fine.	[reply]
Re^3: return a variable from command line execution to perl by Anonymous Monk on Aug 16, 2014 at 14:45 UTC
If you'd like some nicer error handling for the backticks, see `capture` from IPC::System::Simple.	[reply] [d/l]
Re: return a variable from command line execution to perl by kennethk (Abbot) on Aug 15, 2014 at 14:53 UTC
I think the easy answer is backticks. Have your child script print the value, and have the parent script invoke with child as my $value = `perl script.pl`; For more complex/robust options, follow Corion's advice. #11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.	[reply] [d/l]