Problems with Setenv within Perl

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

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Re: Problems with Setenv within Perl by Fletch (Bishop) on Jul 21, 2004 at 15:50 UTC
If you mean you want to modify the parent shell's environment it's because you can't (directly) do that; see `perldoc -q environment`. The work around is to output what the parent should set (e.g. `print "setenv PEOPLE 5033\nsetenv FOO bar\n"`) and then have the parent shell `eval` that output instead.	[reply] [d/l] [select]
Re: Problems with Setenv within Perl by pbeckingham (Parson) on Jul 21, 2004 at 15:49 UTC
Your code `setenv PEOPLE 5033` [download] launches a shell, sets the environment variable in that shell, then the shell quits, and the var is gone. To preserve the value, I believe your only option is to set the var, then exec, but that's hardly a solution for what (little) you describe.	[reply] [d/l]
Re^2: Problems with Setenv within Perl by sgifford (Prior) on Jul 21, 2004 at 19:40 UTC
It's not necessary to use the shell to set a variable. Just: `$ENV{PEOPLE}=5033;` [download] should suffice.	[reply] [d/l]
Re^3: Problems with Setenv within Perl by gmpassos (Priest) on Jul 21, 2004 at 20:39 UTC
Yes, setting the value of %ENV will automatically set the enverioment variable outside the process, and after the process die it will restore the previous values. Note that some keys can't be set, for example, on Win2K we can't set wrong keys like PATH, PATHEXT e HOMEPATH. But if you are just setting a new key it will work just fine. Graciliano M. P. "Creativity is the expression of the liberty".	[reply]
Re^4: Problems with Setenv within Perl by sgifford (Prior) on Jul 22, 2004 at 01:09 UTC
Re: Problems with Setenv within Perl by thor (Priest) on Jul 21, 2004 at 18:17 UTC
Different shells have different semantics for setting environment variables. Consider: #csh/tcsh setenv PEOPLE 5033 #bash/ksh export PEOPLE=5033 #sh PEOPLE=5033 export PEOPLE #perl $ENV{PEOPLE} = 5033 As I allude to above, environment variables in perl are stored in a hash called %ENV. You are free to modify this hash as you see fit. thor	[reply]