I'm trying to recover from a backup disaster that's left me with 4mths of ajax coding down the pan. After deleting the files on XFS I made a dd image of the drive. I've now got to start the process of finding my text based files.

As I'm now back in Windows I've downloaded Grep for it. I've just started:

grep -i -a -B40 -A40 'credentials_login\s\=' d:\image > d:\file.txt

As each search takes a couple hours on the 79Gb file, can I ask whether this IS going to look for 'credentials_login ='? It also needs to look for the string anywhere in the line either start, middle, end, i.e it might not be at the start of the line. Do I need to use extra parameters to tell grep this?

Maybe use the -m option to tell grep to stop after it sees the first matched line with:

grep -i -a -B40 -A40 -m 1 'credentials_login' d:\image > d:\file.txt