Checking environment smart solution

Sun751 has asked for the wisdom of the Perl Monks concerning the following question:

Below i have got the code which works well with right output , But I was wondering if there is any other smarter way to reduce number of code doing same jobs? Any one have any suggestion, please let me know!

#Check environment
sub inspect
{
    my $window,$informix,$oracle,$sql) = @_;

    if ($^O eq 'MSWin32' or $^O eq 'Windows_NT')
    {
        $window=1;
    }
    if ($ENV{FRUNEXT})
    {
        if ($ENV{FRUNEXT} eq 'ifx')
        {
            $$informix=1;
        }
        elsif($ENV{FRUNEXT} eq 'msv')
        {
            $$sql=1;
        }
        elsif($ENV{FRUNEXT} eq 'ora')
        {
            $$oracle=1;
        }
    }
    else
    {
        err_msg( "Database Environment Variable 'FRUNEXT' Not Set: $!\
+n");
        exit;
    }
}
[download]

Cheers!

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Re: Checking environment smart solution by Corion (Patriarch) on Jun 24, 2009 at 07:15 UTC
Also, instead of passing references to your subroutine, you'll be much better off returning a hash, potentially eliminating the `$oracle` and `$informix` variables in favor of a `$database` variable, which contains either `"Oracle"` or `"Informix"`.	[reply] [d/l] [select]
Re: Checking environment smart solution by ikegami (Patriarch) on Jun 24, 2009 at 14:25 UTC
Don't split one value into 4 variables, only one of which can be true. Don't include `$!` in your error message. You didn't do any system calls that set `$!`. Why aren't you using `die`? It'll be much more simpler and reliable to catch exceptions and/or STDERR rather than using `errmsg` everywhere. `sub inspect { return "windows" if $^O eq 'MSWin32' \|\| $^O eq 'Windows_NT'; my $frunext = $ENV{FRUNEXT} or die("Environment variable 'FRUNEXT' not set\n"); return $frunext if $frunext =~ /^(?:ifx\|msv\|ora)$/; return ''; }` [download] Or if you want to do some translation: `my %db_lkup = ( ifx => 'informix', msv => 'sql', ifx => 'oracle', ); sub inspect { return "windows" if $^O eq 'MSWin32' \|\| $^O eq 'Windows_NT'; my $frunext = $ENV{FRUNEXT} or die("Environment variable 'FRUNEXT' not set\n"); return $db_lkup{$frunext} if exists( $db_lkup{$frunext} ); return ''; }` [download] I didn't know if you meant for an unrecognized value of `$ENV{FRUNEXT}` to be an error. It wasn't, so I didn't change that.	[reply] [d/l] [select]
Re: Checking environment smart solution by Anonymous Monk on Jun 24, 2009 at 06:20 UTC
Read perlintro. `err_msg( "Database Environment Variable 'FRUNEXT' Not Set: $!\n") unle +ss $ENV{FRUNEXT} =~ /^ifx\|msv\|ora$/` [download]	[reply] [d/l]
Re: Checking environment smart solution by citromatik (Curate) on Jun 24, 2009 at 07:33 UTC
If you are using Perl 5.10, the `give...when` construction may be of interest here (see perlsyn: `use feature qw/ :5.10 /; # or just: use feature "switch"; sub inspect { my $window,$informix,$oracle,$sql) = @_; $$window=1 if ($^O eq 'MSWin32' or $^O eq 'Windows_NT'); given ($ENV{FRUNEXT}) { when ('ifx') { $$informix=1; } when ('msv') { $$sql=1; } when ('ora') { $$oracle=1; } default { err_msg( "Database Environment Variable 'FRUNEXT' Not Se +t: $!\n") && exit } }` [download] citromatik	[reply] [d/l] [select]