More simply - and keeping the order: 

@arr = ('c1,s1,d1','c2,s2,d2','c1,s1,d2','c1,s2,d3');
@arr = grep{ /(.+),/;
             !$seen{$1}++
           } @arr;
print join$/,@arr;

[download]

Prints: 

c1,s1,d1
c2,s2,d2
c1,s2,d3

[download]

In reply to Re^2: filter array based on 2 fields by hbm
in thread filter array based on 2 fields by webster

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