UNIX for Dummies Questions & Answers

$ cat ./redlotus.sh
#!/bin/ksh

matchfile="redlotus.txt"

matches=`echo "${line}" | egrep -in "Error|Exception" ${matchfile}`
echo "${matches} " | while read line; do
   lineno=`echo "${line}" | cut -d: -f1`
   match=`echo "${line}" | cut -d: -f2`
   echo "Match found - line ${lineno} - ${match}"
   minline=$(( lineno - 5 ))
   [[ "$(( lineno - 5 ))" -lt 1 ]] && minline=1
   sed -n "$minline,$(( lineno - 1 ))p" ${matchfile}
   sed -n "$lineno p" ${matchfile}
   sed -n "$(( lineno + 1 )),$(( lineno + 5 ))p" ${matchfile}

   # note we could just do
   # sed -n "$minline, $((lineno + 5))p" ${matchfile}
   # but i've left this as-is to show you how to grab the previous, and the
   # next, five lines....
done
exit 0