The functionality you seek is traditionally provided by a "config file".

Here is a sample, using Config::Tiny:

$ cat myconfig.ini
var1=hello
var2=perl
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$  perl -MConfig::Tiny -e 'my $Config = Config::Tiny->read("myconfig.i
+ni"); print  $Config->{_}{var1},"\n",  $Config->{_}{var2},"\n"'
hello
perl
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