In addition to my original question I want to find multiple occurrences of the string.

e.g. I have a file called 20071225.log with the contents below:

SUCCESS
1234
2433
SUCCESS
4321
6523
ERROR
5678
8423
SUCCESS
7890
5324
ERROR
3456
3214

I want to display 3 lines below all the occurrences of the line having the string "ERROR" to get the output below:

ERROR
5678
8423
ERROR
3456
3214


I can get the above result with the shell below but I would like a shorter method possibly in one line of command :

Code:

STRING=$1
FILE=$2

DONE=N

while [ $DONE = N ]
do
  sed -n "/$STRING/,\$p" $FILE | sed -n '1,3p'
  sed -n "/$STRING/,\$p" $FILE | sed '1,3d' > $$.txt
  mv $$.txt $FILE
  [[ `cat $FILE | wc -l` -eq 0 ]] && DONE=Y
done