Commands tagged midnight hacking (1)

  • [UPDATE: Now works for multiple connected outputs] I woke up around midnight with an urge to do some late night hacking, but I didn't want a bright monitor screwing up my body's circadian rhythm. I've heard that at night blue (short wavelength) lights are particularly bad for your diurnal clock. That may be a bunch of hooey, but it is true that redder (longer wavelength) colors are easier on my eyes at night. This command makes the screen dimmer and adjusts the gamma curves to improve contrast, particularly darkening blues and greens (Rɣ=2, Gɣ=3, Bɣ=4). To reset your screen to normal, you can run this command: xrandr | sed -n 's/ connected.*//p' | xargs -n1 -tri xrandr --output {} --brightness 1 --gamma 1:1:1 or, more briefly, xgamma -g 1 Note: The sed part is fragile and wrong. I'm doing it this way because of a misfeature in xrandr(1), which requires an output be specified but has no programmatic way of querying available outputs. Someone needs to patch up xrandr to be shell script friendly or at least add virtual outputs named "PRIMARY" and "ALL". . Todo: Screen should dim (gradually) at sunset and brighten at sunrise. I think this could be done with a self-resubmitting at job, but I'm running into the commandlinefu 127 character limit just getting the sunrise time: wget http://aa.usno.navy.mil/cgi-bin/aa_pap.pl --post-data=$(date "+xxy=%Y&xxm=%m&xxd=%d")"&st=WA&place=Seattle" -q -O- | sed -rn 's/\W*Sunrise\W*(.*)/\1/p' I hope some clever hacker comes up with a command line interface to Google's "OneBox", since the correct time shows up as the first hit when googling for "sunrise:cityname". . [Thank you to @flatcap for the sed improvement, which is much better than the head|tail|cut silliness I had before. And thank you to @braunmagrin for pointing out that the "connected" output may not be on the second line.] Show Sample Output


    3
    xrandr | sed -n 's/ connected.*//p' | xargs -n1 -tri xrandr --output {} --brightness 0.7 --gamma 2:3:4
    hackerb9 · 2010-10-24 10:45:57 11

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands


Check These Out

calulate established tcp connection of local machine
If you want prepend/append text just wrap in echo: $echo Connected: `netstat -an|grep -ci "tcp.*established"`

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

Show IP Address in prompt --> PS1 var
when working with many machines in a computer lab need to know the IP addr is very large, this is a simplistic solution to make things easier

check open ports
Tested in Linux and OSX

Use Perl like grep
Much better alternatives - grep-alikes using perl regexps. With more options, and nicer outputs.

google chart api
http://chart.apis.google.com/chart?chs=450x200&cht=p3&chtt=Browser+Usage+on+Wikimedia&chl=IE%2834.2%%29|Firefox%2823.6%%29|Chrome%2820.6%%29|Safari%2811.2%%29|Opera%285.0%%29|Android%281.9%%29|Other%283.5%%29&chd=t:34.2,23.6,20.6,11.2,5.0,1.9,3.5

Makefile argument passing
This would allow reference of $(VAR) (if defined) with the value 'foobar' within the Makefile.

View the current number of free/used inodes in a file system
tune2fs also provides the same information . But the information does not give the current usage , it gives the information when the file system was last mounted. http://www.zaman4linux.in/2010/10/using-up-all-the-free-inodes.html

List last opened tabs in firefox browser

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"


Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: