Using vi as a hex editor

Sometimes I find it useful to switch to hex mode when editing a file in vi. The command for switching is not very obvious so thought I’d share…

So, open a file in vi as usual. To switch into hex mode hit escape and type:

:%!xxd

And when your done and want to exit from hex mode hit escape again and type:

:%!xxd -r

Okay, so this isn’t actaully switching to vi’s ‘hex mode’; vi doesn’t have one. What the above actually does is to stream vi’s buffer through the external program ‘xxd’.