$ echo "unix" | awk 'BEGIN {FS=OFS=""} END { if (!found) print "FAILED" }
$1 == "u" { print "PASSED"; found++ }
'
PASSED

$ echo "unix" | awk 'BEGIN {FS=OFS=""} END { if (!found) print "FAILED" }
$1 == "g" { print "PASSED"; found++ }
'
FAILED