count columns awk

count columns separated by space

awk '{ print NF }' <<< 'a bc d ef'

count columns separated by comma

awk -F, '{ print NF }' <<< 'a,b,c'

count columns separated by tab

echo -e 'a\tb\tc' | awk -F'\t' '{ print NF }'

get number of columns from a file

awk '{ print NF }' file

get sum of columns from a file

awk '{ print NF }' file | sort | uniq -c

print only lines that have 3 columns

echo -e 'a b c\nx y' | awk 'NF == 3'

print only lines that have 7 columns from a file

awk 'NF == 7' file