Question

I have a system that is composed of both bash scripts and Perl scripts.

Is there a safe way to specify config values that are used by both Perl scripts and shell scripts?

We need both as there are common elements which are simple MY_VAR=toto declarations along with Perl specific config values, e.g. hashes.

BTW We don’t have the Env module available in our hardened Perl build.

Answer 1

You don’t have to have Env to be able to access environment variables. The following excerpt from the Env documentation makes this plain:

Perl maintains environment variables in a special hash named %ENV.
For when this access method is inconvenient, the Perl module Env
allows environment variables to be treated as scalar or array
variables.

%ENV makes constructing “config” hashes in Perl quite simple. In the following example, it’d probably be clearer to stick with %ENV itself:

my %config;
my @env_vars = qw/ foo bar baz quux /;
@config{@env_vars} = @ENV{@env_vars};