oh, unix

Cat to or from clipboard in Terminal

2011-06-27T07:22:00.000-07:00

On a Mac, man pbcopy or pbpaste to see how to redirect into or out of your pasteboard/clipboard. With pbpaste, -Prefer txt can be useful to ensure ascii output.

cat file.txt | pbcopy
pbpaste -Prefer txt > out.txt

Yay.

Rotate tablet PC screen with a single button in Ubuntu 11.04

2011-06-21T15:10:00.000-07:00

Someone asked me for help on tablet screen rotation in Ubuntu for an older (2006) Lenovo X60 tablet PC - in particular, the desire was to make it as simple as possible to flip the screen 180 degrees since on this model, for right-handers, a flipped screen is more comfortable ergonomically for....tableting. Simplicity suggested a big noticeable blue button on the Unity 11.04 Launcher (the slide out bar on the left). Being new to Unity myself, there were a couple of quirks to figure out.

My goal was to add a button to the launcher that would fire off a shell script. The script relies on xrandr (for screen rotation) and xsetwacom (for the stylus to map correctly to the rotated screen). They're easy to use after some manpage-skimming and they don't require elevated privileges.

Now, how to add it to the Unity launcher bar? Either you can create a .desktop file from scratch or you can use the menu option for creating a launcher, and repurpose the .desktop to point to your script. Here's the one I used, which also points to a serviceable picture of a generic monitor icon, courtesy of Gnome.

After dragging it to the launcher and a re-login, the button does the intended trick.

And here are a couple of useful links to ubuntuforums.org posts that told me everything I needed to know to rush out the above tidbits.

Keeping your idle ssh connection alive (the wrong way)

2011-06-02T16:36:00.000-07:00

Need to keep an ssh connection alive? Maybe you're doing it wrong - use nohup. Can't? Got some weird corner case that needs a living ssh connection with some process doing something in the foreground? You could always use expect/pexpect. But that's too much trouble! This python script is a quick and dirty way of doing it wrong:
import time

import sys

def infinite():

i = 0

while 1:

print "been asleep for ", i ,"hours"

time.sleep(60 * 60)

i += 1

def sleeper(minutes):

print time.strftime("%a, %d %b %Y %I:%M:%S +0000", time.localtime())

time.sleep(minutes * 60)

print 'awaking'

print time.strftime("%a, %d %b %Y %I:%M:%S +0000", time.localtime())

def main():

if len(sys.argv) != 2:

print "fail!"

return

if sys.argv[1] == "infinite":

infinite()

else:

sleeper(int(sys.argv[1]))

if __name__ =="__main__":

main()

Usage:

python keepawake.py 60

Sleeps for 60 minutes

python keepawake.py infinite

sleeps until you Ctrl+C

If you're using this often (why?! You're doing it wrong!) then of course just throw in an alias within your .bashrc:

alias keepawake='python ~/path/to/keepawake.py'

And now you can call:

keepawake 60

keepawake infinite

whenever your heart desires.

Get colors from Terminal, and pasting into vim from other programs

2011-06-02T16:13:00.000-07:00

In seeking an answer to copying terminal output with ANSI-style colors, thanks goes to this question. I wanted to get colored output from Mac OS X's Terminal, and the easiest way was to print to a pdf and copy from there.

Also, here's the right way to paste into vim from an external source (such as a gist) because I seem to forget this (since I'm usually pasting from vim into vim). To avoid vim's auto-indenting or auto-commenting as the lines are written from the pastebuffer into vim, to enter paste mode just
:set paste
and then, back in insert mode, Ctrl+v or Command+v or whatever suits your fancy. Once you're done,
:set nopaste
You've now sidestepped all that pesky smart indentation/commenting.

Usable parenthesis matching in vim

2011-06-02T15:40:00.000-07:00

I'll post my messy hodgepodge vim configuration below but the only part worth highlighting (no pun intended) is the following trick for making vim not do terribly confusing parenthesis matching:

hi MatchParen cterm=bold ctermbg=none ctermfg=red

Serviceable explanation here. It's pretty self explanatory though: this changes the foreground (and background if you so choose - yellow is serviceable) of the matched parenthesis to something a little more distinctive so you don't lose track of where your cursor is. Default matching always makes me confused whenever I'm navigating around, especially in parenthesis-heavy code. And I guess it's nice that you can just use color names like white or green, even though that bugs me, because I have no idea if it will support, say, fuchsia... or glaucous. (I think it probably just supports basic 256-color palette names, but feel free to comment with a link to the specification or vim source)

And for posterity, my whole vimrc, with some comments mixed in:

More vim tips to come in the next post.