use Cwd;
my $path=cwd();
 
sub proc{
    my ($file) = @_;
    # (...)
    $pathC = $path . "/$file";
    open INPUT, "zcat $pathC|" or dealError($cpath);
        while($line = <INPUT> ){
            eval($line);
            # (…) data proccessing irrelevant to the problem
        }
    close INPUT;
}
 
sub init{
    (...) #Initializing @lista ("system "ls"" plus a bunch of tests)
    for my $fileName (@lista){
        proc($fileName);
    }
}
 
init;
 
#------------------------------------------------------------------
sub dealError{
    my ($path) = @_;
    open(STDIN, "-"); #Opens standard INPUT
    print "\n!!ATENTION:\n\tdealError: Could not open file $cpath\n";
    print "Check the problem with the file and type GO to continue\n";
    while($line = <STDIN>){
        if ($line =~ m/GO/){
            open INPUT, "$cpath" or dealError($path);
            close STDIN;
            last;
        } else {
            print "Check the problem with the file and type GO to continue\n";
        }
    }
}