An effective solution doesn't necessarily mean Perl in this case.

PATH is most likely set, assuming you're using bash by the file .bash_profile for login shells or by .bashrc for non-login shells in your home directory.

By the description I was assuming that you were interested in setting the PATH for your shell use.

From perldoc perlvar: "$ENV{expr} - The hash %ENV contains your current environment. Setting a value in "ENV" changes the environment for any child processes you subsequently fork() off."

This means a script cannot modify the ENV for it's parent shell, only for it's children processes. A shell is a script's parent process.

As you've been told, you can't change your parent process's environment. If you don't mind having an extra shell process sitting around, however, you can exec '/bin/sh'.

Another possibility is outputting shell commands from your perl script and eval'ing that output in your shell.

Unless you have a really good reason—like you have real complex things you want to do to your environment—you're probably better off just sourcing a shell script.

-sauoq
"My two cents aren't worth a dime.";

As merlyn points out, perlfaq8 answers this. However, it then refers you to another FAQ - comp.unix.questions. That can be found via google easily enough. Just FYI - I use this at work all the time. I have a table that I transform into aliases at work such that I can have these aliases do the "right thing" on AIX, Sun, HP, and Linux boxes. I do that via perl - your path change would fit the same way.

eval `/common/tools/mkAliases`
[download]

my $table = read_table();
foreach my $key (keys %$table)
{
  print "alias $key '$table->{$key} $current_user';\n";
  print "alias ${key}r '$table->{$key} root';\n";
  # etc.
}
[download]

What this is doing, then, is creating a shell script in perl that the shell can then run to make the changes to the current shell process.