If you're in a csh shell (or most other shells), then yes, entering source sge_sigma.csh at the command line will cause the contents of that file to be interpreted and take effect in the current shell. 

bannor:~/work/perl/monks$ csh
bannor:~/work/perl/monks> cat test.csh
setenv MYTEST "This is a test."
bannor:~/work/perl/monks> echo $MYTEST
MYTEST: Undefined variable.
bannor:~/work/perl/monks> source test.csh
bannor:~/work/perl/monks> echo $MYTEST
This is a test.

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You can't do this from within a Perl script, because it's a sub-process of the shell, so it can't change its parent's environment. To put it another way, you can change environment variables within a Perl script by use of the %ENV hash, and those will be inherited by any child processes that your Perl script spawns, but they can't go "upstream" to the parent process.

Aaron B.
My Woefully Neglected Blog, where I occasionally mention Perl.

In reply to Re^3: Environment Variable Setting by aaron_baugher
in thread Environment Variable Setting by austinj

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