What does the syntax-- $ENV{'REMOTE_HOST'} --mean in Perl?

Bassam · 03-29-2004, 04:43 AM

Hello Guys,
I was reading some refernce about CGI with Perl programming and I found in one of the programes the following statment

Code:

$remote_host = $ENV{'REMOTE_HOST'};

Can anyone tell me what does this syntax mean?, what exactly the brace brakets mean?

I am still new in Perl programming, but I have not seen such syntax before?
I would be thankful if you tell me where can I read about such syntax.

Thanks for the help
Bassam

bigearsbilly · 03-29-2004, 05:36 AM

$ENV is a hash (associate array) of the environment
variables available and their values.
so this means get the value of the env.
variable REMOTE_HOST (if it exists).

It doesn't only count in CGI it works for normal shell
environment too:

observe:

Code:

billym.primadtpuat>echo $PWD
/export/home/billym
billym.primadtpuat>
billym.primadtpuat>perl
print "\n\n$ENV{'PWD'}\n\n";
^D

/export/home/billym

eric.r.turner · 03-31-2004, 08:44 AM

Quote:

Originally posted by bigearsbilly
$ENV is a hash (associate array) of the environment
variables...

I know this is a bit picky, but %ENV is the hash (not $ENV.) The $ in $ENV{'REMOTE_HOST'} indicates that the value associated with the REMOTE_HOST key is a scalar.

bigearsbilly · 03-31-2004, 08:54 AM

good point well made.

regards, billy