sub func1{
WriteTOLog($Arga,$Argb,$Argc,$Argd); }
 ... do a bunch of things 
<code>
file b.pl
<code>
sub func2{
WriteTOLog($Arga,$Argb,$Argc,$Argd); }
 ... do a bunch of things 
<code>
file c.pl
<code>
sub func3{
WriteTOLog($Arga,$Argb,$Argc,$Argd); }
 ... do a bunch of things 
<code>
file log.pl
<code>
sub WriteToLog($,$,$,$){
  local ($var) = @_;
  # do its fike IO stuff
}