Solaris

-bash-3.00$ ./kiran.sh ab 0 0 ./testfile
abc
abc
abc
-bash-3.00$ ./kiran.sh ab 0 2 ./testfile
abc
1
2
abc
1
2
abc
.
!
-bash-3.00$
-bash-3.00$ cat ./kiran.sh
#!/bin/ksh
# no -C option to grep? no fear...
# usage:
#   scriptname "searchterm" lines_before lines_after inputfile

matchstring="$1"
lines_before="$2"
lines_after="$3"
matchfile="$4"

matches=`echo "${line}" | egrep -n "${matchstring}" ${matchfile}`
if [ "$?" -ne "0" ]; then
   echo "No match" >&2
   exit 1
fi
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 - ${lines_before} ))
   [[ "$(( lineno - ${lines_before} ))" -lt 1 ]] && minline=1
   [[ "${lines_before}" -gt "0" ]] && \
   sed -n "$minline,$(( lineno - 1 ))p" ${matchfile}
   sed -n "$lineno p" ${matchfile}
   [[ "${lines_after}" -gt "0" ]] && \
   sed -n "$(( lineno + 1 )),$(( lineno + ${lines_after} ))p" ${matchfile}
done

exit 0