YAPM (Yet Another Perl Module) which I just uploaded to PAUSE.
This module enables the user to alter or query an unrelated process's
Windows allows a process with sufficient privilege to run code in another
process by attaching a DLL. This is known as "DLL injection", and is used here.
use Win32::EnvProcess qw(:all);
use Win32::EnvProcess qw(SetEnvProcess);
my $result = SetEnvProcess($pid, env_var_name, [value], ...);
use Win32::EnvProcess qw(GetEnvProcess);
my @values = GetEnvProcess($pid, env_var_name, [...]);
use Win32::EnvProcess qw(DelEnvProcess);
my $result = DelEnvProcess($pid, env_var_name, [...]);
use Win32::EnvProcess qw(GetPids);
my @pids = GetPids($exe_name);
This is another case where a question on perlmonks generated the interest. How do I get the child to create/alter an environment variables in the parent? Had this been on UNIX then the answer would be simple - you can't without having co-operating proceses. On Windows however DLL injection makes this possible.
I have done a brief investigation on how this might be achieved on Linux, but I don't think it can fly. The API ptrace(2) is a start, but the problem is in creating a thread in the host. Addresses in the host can be changed, but the environment block is not at a fixed location so far as I know, and without a symbol table I'm not sure how you would find it.