Removing duplicate lines 2

[ianicr]

I have a file that has name/address/phone number data in eg.
Mr,T,Smith,1 New Street,01159845671
Mr,T,Smith,1 New Street,01159872345

I need to remove these duplicates but cannot use sort |uniq because they are not exactly the same. Is there a way to just check the first 4 fields and remove one of the lines?

 

[Ygor]

sort -t, -u -k1,4 infile

 

[ianicr]

Cheers. I did check this out but I thought it would only print the fields in the key. Oh well my mistake. Thanks mate