Number of fields returned by awk

Question

Is there a way to get awk to return the number of fields that met a field-separator criteria? Say, for instance, my file contains

a b c d

so,

Answer 1

awk(1) on FreeBSD does not recognize --field-separator. Use -v instead:

echo "a b c d" | awk -v FS=" " "{ print NF }"

It is a portable, POSIX way to define the field separator.