Answer by heemayl for Grep for multiple strings, show number of lines after one of the strings (but not the other)

You can't do that using one go of grep. You need to use two grep instances :

grep 'string1' file; grep -A 5 'string2' file

If you want to run the second upon success of the first one :

grep 'string1' file && grep -A 5 'string2' file