Bash - Display a numbered segment of a file

# when only the start_line is specified, a range of 10 lines before and after # that line will be numbered and displayed. when start_line and end_line are # specified, those lines and all those between will be numbered and displayed # # @param String $filename the text file with the content # @param Integer $start # @param Integer Optional $end # # Examples: # # Display lines 90 - 110. Line 100 is the middle line of content # $ seg error.log 100 # # Display lines 100 through 140. # $ seg error.log 100 140 # # function numseg() { range=10 filename=$1 if [[ -z $3 ]]; then start=$( calc $2-$range) end=$(calc $2+$range) else start=$2 end=$3 fi nl $filename | awk "NR >= $start && NR <= $end " }