Crude file recovery on an ext3 partition

I was working on project for the past couple days and was just about to enable it permanently. Before that, though, I ran a ‘yum update’. I wasn’t paying attention to what was updated though, and the program that I was working on got updated during the process. My modified version of the script was wiped out

Not willing to throw away a couple days worth of modifications, I was desperate to recover my changes. Fortunately the script was still running, so I know that it wasn’t really deleted from the disk yet. Since the file was still locked, the file system just marked the file as deleted, but hadn’t really deleted it. A ‘lsof’ showed that it was still there but deleted. It gave me an inode number, but I couldn’t find any way to use that.

Instead, I came up with a pretty crude way to find my script:

cat /dev/sda1 | strings | grep -A 10000 -B 10000 "some_string_unique_to_my_script" > /tmp/somefile

This cats out the actual content of the device file, searches for strings in it, and then grep’s for your unique string, and saves 10,000 lines before and after it into /tmp/somefile. I was then able to look through /tmp/somefile and find my script in there. It is not in a format that you can just copy/paste out. But all the significant pieces were in there, and I was able to recover everything that I needed without rewriting everything.

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