inet_ntoa and pack are your friends.

$ perl -MSocket=inet_ntoa -le 'print inet_ntoa(pack("N",shift||2130706
+433))'
127.0.0.1
$ perl -MSocket=inet_ntoa -le 'print inet_ntoa(pack("N",shift||2130706
+433))' 3232235777
192.168.1.1
[download]

Update: And since you've asked about the reverse:

$ perl -MSocket -le 'print unpack("N",inet_aton(shift||"192.168.1.1"))
+'                
3232235777
$ perl -MSocket -le 'print unpack("N",inet_aton(shift||"192.168.1.1"))
+' 127.0.0.1
2130706433
[download]