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:

http://explainshell.com/explain?cmd=rsync+-Phavz+--stats

http://explainshell.com/explain?cmd=rsync+-Phavz+--stats+remote%3A%24DIR%2F+%24DIR

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
https://linuxconfig.org/passwordless-ssh

** make a key
ssh-keygen

** 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

http://stackoverflow.com/questions/1085170/how-to-achieve-code-folding-effects-in-emacs/1211325#1211325
https://emacs.wordpress.com/2007/01/16/quick-and-dirty-code-folding/

M-1 C-x $ and magic happens!

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

* hg merge not graphical avoid meld >>>>>>> <<<<< =====

* hg merge not graphical avoid meld >>>>>>> <<<<< =====
HGMERGE=merge hg rebase --keep --source ptm-eftest-source --dest origin/master

hg bisect

* hg bisect
https://www.mercurial-scm.org/repo/hg/help/bisect

** basic commands
hg bisect --reset
hg bisect --bad
hg bisect --good

** help is surprisingly readable
hg bisect --help
hg bisect --help --verbose

** automatic usage
hg bisect --reset
hg bisect --bad 34
hg bisect --good 12
hg bisect --command "make && make tests"

hg clean

there's no equivalent to git clean, but

hg status -iu                          # to show
hg status -iun0 | xargs -r0 rm         # to destroy

removes all the ignored (i) and unversioned (u) files that may be lying around (including emacs backup files etc, may be better to do make clean)


and then

hg update -C -r xxxxx

restores the state of the parent (note just -C puts you to tip rather than to where you are)

Mercurial hg diff patch wiggle

remember diff is from 30652 to 30659 to make a patch that will turn 30652 into 30659

hg diff -r 30652 -r 30659 >~/patch
patch  -p1 <~/patch

if the patch fails to apply, the bits can be wiggled in like:

wiggle --replace mc/main/ncsi.c mc/main/ncsi.c.rej
wiggle --replace mc/main/pdma.c mc/main/pdma.c.rej

theoretically

wiggle -rp ~/patch

should do the whole thing, but it can't create files.