Shell Programming and Scripting

Hi,
I meet an problem that it cannot change Terminal environment variable in a perl or bash script.
This change can only exist and become effective in script lifetime.
But I want to make this change take effect in current opened Terminal.
In our view, the thought seems to be impossible,
As far as I know, a Source Tool called modules which written by C or Tcl can realize this process.
you can view in .
Modules -- Software Environment Management.

My problem is that how to change current opened Terminal through a perl or bash script?

Thanks firstly.

Code:

cat pathenv
export PATH="$PATH:/opt/X11/bin"

echo $PATH
/usr/local/bin:/usr/local/sbin:/opt/local/bin:/opt/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin

source pathenv

echo $PATH
/usr/local/bin:/usr/local/sbin:/opt/local/bin:/opt/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin

Since variables do not go backwards that way, your perl script must create a new shell.

Code:

#!/usr/bin/perl

$ENV{MYVAR}="asdf";

exec 'bash', '-sh';

Code:

$ echo $MYVAR

$ exec ./myscript.pl # Using exec means you don't need to 'exit' twice after
$ echo $MYVAR
asdf

$

A more flexible version:

Code:

#!/usr/bin/perl

$ENV{MYVAR}="asdf";

my $shell=shift;
if($shell) {
        exec $shell, @ARGV;
}
else
{
        exec "bash", "-sh";
}

When not given a shell it assumes bash, otherwise it runs what you tell it on the commandline.

You did a great job.
Thanks very much!
I will try do this method and verify it whether fulfill my requirement.

---------- Post updated 07-25-13 at 08:32 AM ---------- Previous update was 07-24-13 at 09:33 AM ----------

I have already used your solution, but there is some problem as follows:
Our shell version is tcshrc, the terminal prompt like cm280:/home/wch> set in .tcshrc.
But the terminal prompt will become '%' only after executing './1.pl csh' using your method although the variable MYVAR has been changed as 'asdf'.

There cannot change Termina environment MYVAR as 'asdf' at all when executing option './1.pl csh -f'.

Is this any good suggestion and solution in tcshrc ?
I am looking forward to your answer.
Thanks greatly.

-f is the opposite of what you want -- that forces it to not load your tcshrc.

Try csh -l to force it to be a login shell. -l must be the only argument.

Unfortunately, '1.pl csh -l' will also load .cshrc file again. and all variable including MYVAR var will be recovered as setted in .cshrc.

I have tried all csh commandline argument respectively, only -f will not load .cshrc and can modify variable MYVAR.

But after executing '1.pl csh -f', the Terminal Prompt will become '%' only not keeping raw style ctm:/home/wch>

Do you have any good ideas suggestion for me?
Could you try all process as described above in your cshell environment?
Thanks.