Incrementing a variable inside a Bash loop

Question

I\'m trying to write a small script that will count entries in a log file, and I\'m incrementing a variable (USCOUNTER) which I\'m trying to use after the loop

Answer 1

• Always use -r with read.
• There is no need to use cut, you can stick with pure bash solutions.
  • In this case passing read a 2nd var (_) to catch the additional "fields"
• Prefer [[ ]] over [ ].
• Use arithmetic expressions.
• Do not forget to quote variables! Link includes other pitfalls as well

while read -r country _; do
  if [[ $country = 'US' ]]; then
    ((USCOUNTER++))
    echo "US counter $USCOUNTER"
  fi
done < "$FILE"