use warnings;
use strict;

while ( <DATA> ) {
    print "$1\n" if /^(\w+[\w,]+\w+)$/ && !/,,/;
}

__DATA__
!@#$as3dfa
,sdfas3df,
asd3fsa,,a3sdf
as3df,asdf3,3asdf,asd3f
sad3fasdjasdfkasdfklas3jf
3sad3fasdjasdfkasdfklas3jf
3sad3fasdjasdfkasdfklas3jf3