First Match - awk
consider file having values:
foo
boo
too
and another one:
foo,1
foo,2
boo,1
soo,1
How to get only first match from the 2nd file, where output will be:
foo,1
boo,1
How about
$ awk -F, 'NR==FNR {a[$1]; next} $1 in a {print; delete a[$1]}' file1 file2 foo,1 boo,1