Friday, August 4, 2017

grep just highlight

Trick is to use ^ to every line with a start-of-line. Since that's unprintable it won't get highlighted.

So to list all the files with arista in the name, but highlight the objects:

find . -name "*arista*" | grep -E '^|\.o|.so'

Friday, May 19, 2017

Find .c or .h or .py files

You can use a regular expression with find:

find . -regex '.*cisco.*\.\(c\|h\|py\)'

finds all cisco-related .c .h or .py files.

Monday, April 24, 2017

Friday, February 24, 2017

How to fix a spelling mistake in lots of files

First, is it all version controlled? 
And are any of the files currently in editor buffers? Close if so.

There are two different versions of rename

the perl-rename that I was expecting

$ rename 's/monkey/reproducer/g' *monkey*

and the rename from util-linux 2.28.2 that's actually on my Fedora box

$ rename monkey reproducer *monkey*

need to do this in all affected directories, there's probably something you can do with find if there are lots

and then to change the text in all the files (recursive)

$ grep -rl monkey . | xargs sed -i 's/monkey/reproducer/g' 

finally change it in .bash_history too

sed -i 's/monkey/reproducer/g' ~/.bash_history

note that this will corrupt the history of all the commands you just typed.

Tuesday, February 14, 2017

rsync and explainshell

My current favourite rsync invocation is:

$ DIR=/home/jla/stuff

$ rsync -Phavz --stats remote:$DIR/  $DIR

and my current favourite way of figuring out what the options mean is:

Although it doesn't mention the crucial trailing slash on the source directory, which means that you end up copying /home/jla/stuff/file to /home/jla/stuff/file rather than to /home/jla/stuff/stuff/file.

Tuesday, January 31, 2017

passwordless ssh

* passwordless ssh

** make a key

** copy it to every machine you can log in to
as you
ssh-copy-id jla@furnace

or as root
ssh-copy-id root@manftest59

Emacs code folding

* Emacs code folding

M-1 C-x $ and magic happens!

As usual, it’s white magic: C-x $ will bring your code back.