Tip:

if(-e "/var/lib/asterisk/sounds/currentconditions.ulaw") {
        unlink("/var/lib/asterisk/sounds/currentconditions.ulaw");
}
if(-e "/var/lib/asterisk/sounds/planets.ulaw") {
        unlink("/var/lib/asterisk/sounds/planets.ulaw");
}
if(-e "/var/lib/asterisk/sounds/forecast.ulaw") {
        unlink("/var/lib/asterisk/sounds/forecast.ulaw");
}
[download]

can be simplified to

unlink(
   "/var/lib/asterisk/sounds/currentconditions.ulaw",
   "/var/lib/asterisk/sounds/planets.ulaw",
   "/var/lib/asterisk/sounds/forecast.ulaw",
);
[download]

unlink tries to delete all the files, even if it can't delete some of them.

>copy nul a
        1 file(s) copied.

>copy nul c
        1 file(s) copied.

>dir /b
a
c

>perl -e"unlink qw( a b c )"

>dir /b

>
[download]