Replace first word after string INITIAL

Shell Programming and Scripting
1

Hi

I have a file with hundreds of lines, some of the lines have word INITIAL followed by some numbers like
....INITIAL 1234535 ....
....INITIAL 5768644 ....

I would like to replace the number after word INITLA with 4K how can I do it? Cant get my heard around this! The string is always numeric and can have any length..

Thank you

2 
perl -i -pe 's/(?<=INITIAL )[0-9]+/4k/' file
3

Thanks!!!!!!

4

Since my sed version doesn't seem to deal with the + sign :

sed 's/\(INITIAL\) [0-9][0-9]*/\1 4k/g' file

otherwise it could be written this way:

sed 's/\(INITIAL\) [0-9]+/\1 4k/g' file

or just

sed 's/INITIAL [0-9]+/INITIAL 4k/g' file

If you don't have more than one occurrence of "INITIAL" pattern within a line, you can then remove the "g" letter which is after then ending slash