Removing lines with strings from text files on Linux/Mac OS X

Category:

Tutorials > Operating Systems > MacOS X > Tips and Tricks

I used this technique to remove strings from bash history file containing passwords and other sensitive data on a Mac OS X shell (command line). In my case, this was a precautionary measure to make sure I erase any sensitive data from history files. For example, this is important for folks who enter mysql username and password on command line (with the 'mysql -p' command).

Lets say you want to remove lines containing the string 'password' (without quotes) from bash history file, then you'd use the awk command below. Please make a secure/encrypted backup copy of the original file in case you need it in future or have to restore for any reason:

awk '!/password/' ~/.bash_history > temp && mv temp ~/.bash_history

Please note that the command above erases lines and prints remaining content into a temporary file (named temp in example above). Then, moves (using mv in example above) the temporary file to original bash_history file.

Another technique is to use sed in a similar fashion.

sed '/password/d' ~/.bash_history > temp && mv temp ~/.bash_history

Bash history is stored in ~/.bash_hisotry file for the current user.

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