Commands by taurus (1)

  • I wrote a script called bootstrap.py to delete the database, then load a new database with initial values. With this single-line shell loop, when I need to make a schema change (which happens often in the early stages of some projects), I hit ctrl-C to stop the running Django server, then watch bootstrap.py do its thing, then watch the server restart. Show Sample Output


    -3
    while true ; do scripts/bootstrap.py ; ./manage.py runserver ; done
    taurus · 2009-03-27 04:43:54 1

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

Remove embedded fonts from a pdf.
It's sometimes useful to strip the embedded fonts from a pdf, for importing into something like Inkscape. Be warned, this will increase the size of a pdf substantially. I tried this with only gs writing with -sDEVICE=pdfwrite but it doesn't seem to work, so I just pipe postscript output to ps2pdf for the same effect.

Setup an ssh tunnel
Uses ssh as tunnel tunnel for an other connection. -f runs ssh in the background -N tell that there is no command to run -L deals with the forwarding aspect where the first number is the local port number, the second is parameter is the name of the server to forward to and the third parameter is the port number on that server. The last part of the command is the usual ssh form consisting of the user name and remote server name

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

File rotation without rename command
Rotates log files with "gz"-extension in a directory for 7 days and enumerates the number in file name. i.e.: logfile.1.gz > logfile.2.gz I needed this line due to the limitations on AIX Unix systems which do not ship with the rename command.

Replace the content of an XML element
Replaces "650" with "999" in simple.xml. xml used - http://www.w3schools.com/xml/simple.xml

Download and install the OpenStore on the Ubuntu Phone
This will download and install the latest version of the open store on the ubuntu phone, this store includes unconfined applications such as the TweakGeek and the Ubuntu Touch Tweak Tool. You can see the install instructions from here: https://open.uappexplorer.com/docs#install

Rapidly invoke an editor to write a long, complex, or tricky command
Next time you are using your shell, try typing ctrl-x e (that is holding control key press x and then e). The shell will take what you've written on the command line thus far and paste it into the editor specified by $EDITOR. Then you can edit at leisure using all the powerful macros and commands of vi, emacs, nano, or whatever.

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Create a tar archive using xz compression
compress directory archive with xz compression, if tar doesn't have the -J option (OSX tar doesn't have -J)

Check whether laptop is running on battery or cable


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: