Using sed to replace a number greater than a specified number at a specified position

Question

I need to write a script to replace all the numbers greater than an specified number which is in following position.

1499011200 310961583 142550756 313415036 14         


        

Answer 1

This might work for you (GNU sed):

sed -r '/^\S+\s+(300000000|[1-2][0-9]{8}|[0-9]{1,8})\s/!c change' file

If it's 300000000 or less keep it, otherwise change it.

Or using substitution:

sed '/^\S\+\s\+\(300000000\|[1-2][0-9]\{8\}\|[0-9]\{1,8\}\)\s/!s/^\(\S\+\s\+\).*/\1250000000 XXXX XXXX XXXX/' file