Count number of lines under each header in a text file using bash shell script

Note: Bash version 4 only (uses associative arrays) #!/usr/bin/env bash FILENAME="$1" declare -A CNT while read -r LINE || [[ -n $LINE ]] do if [[ $LINE =~ ^head ]]; then HEADLINE="$LINE"; fi if [ ${CNT[$HEADLINE]+_} ]; then CNT[$HEADLINE]=$(( ${CNT[$HEADLINE]} + 1 )) else CNT[$HEADLINE]=0 fi done < "$FILENAME" for i in "${!CNT[@]}"; do echo "$i: ${CNT[$i]}"; done Output: $ bash countitems.sh input head-abc: 4 head-xyz: 3 Does this answer your question @powerrox ?

If you don't consider sed a high-level language, here's another approach: for file in head-*; do echo "$file: \c" sed -n '/^head-/,${ /^head-/d /^item[0-9]/!q p } ' <$file | wc -l done In English, the sed script does Don't print by default Within lines matching /^head-/ to end of file Delete the "head line" After that, quit if you find a non-item line Otherwise, print the line And wc -l to count lines.