If the exec("/path/to/file.cgi") is meant to be called from a script that you run in a command-line shell, the easiest way to provide the cgi parameters to the cgi script that is being exec'd is to include them as a command-line arg, and in this case, it would be really important to use the "list" style invocation of exec():

my $cgiprog = '/path/to/filename.cgi';
my $cgiparams = 'action=task1&user=me';

exec( $cgiprog, $cgiparams );
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Assuming that the cgi script being exec'd in this fashion is using the CGI module, $ARGV[0] will automatically be treated as the QUERY_STRING.