Commands by twjolson

Commands by twjolson (5)

sorted by

Renames all files in the current directory such that the new file contains no space characters.
This is sample output - yours may be different.
-2

rename 's/ /_/g' *

twjolson · 2011-07-04 06:21:27 1
ROT13 using the tr command

Will rot 13 whatever parameter follows 'rot13', whether it is a string or a file. Additionally, it will rot 5 each digit in a number
This is sample output - yours may be different.
-5

function rot13 { if [ -r $1 ]; then cat $1 | tr '[N-ZA-Mn-za-m5-90-4]' '[A-Za-z0-9]'; else echo $* | tr '[N-ZA-Mn-za-m5-90-4]' '[A-Za-z0-9]'; fi }

twjolson · 2011-03-18 09:59:41 0
Generate MD5 of string and output only the hash checksum
This is sample output - yours may be different.
-1

echo -n "String to MD5" | md5sum | awk '{print $1}'

twjolson · 2011-03-05 02:37:28 0
Add a list of numbers

Works for any mathematical operation, even converting numbers from one base to another. Show Sample Output
This is sample output - yours may be different.
```
10
```
-3

echo "1+2+3+4" | bc

twjolson · 2011-02-24 03:08:00 0
Watch the progress of 'dd'

dcfldd is a forensic version of dd that shows a process indicator by default.
This is sample output - yours may be different.
1

dcfldd if=/dev/zero of=/dev/null

twjolson · 2010-05-14 17:37:03 2

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

Sum columns from CSV column $COL

More of the same but with more elaborate perl-fu :-)

Extract audio track from a video file using mencoder

Extracts an MP3 encoded audio stream from an input video file.

List all files ever added in git repository

recursive search and replace old with new string, inside files

If you can install rpl it's simpler to use and faster than combinations of find, grep and sed. See man rpl for various options. time on above operation: real 0m0.862s, user 0m0.548s, sys 0m0.180s using find + sed: real 0m3.546s, user 0m1.752s, sys 0m1.580s

Show sorted list of files with sizes more than 1MB in the current dir

no fancy grep stuff here.

multiline data block parse and CSV data extraction with perl

extract data in multiline blocks of data with perl pattern matching loop

Combines an arbitrary number of transparent png files into one file

This one liner; combines all sequentially numbered files; in this example IMG_0001.png to IMG_1121.png by generating the shell script, making the shell script executable and then running the shell script to combine the 1121 png into a single png file named _final.png tested on Mac OS X 10.6.3 with ImageMagick 6.5.8-0 2009-11-22 Q16 http://www.imagemagick.org

encode image to base64 and copy to clipboard

I use it for embedding images in CSS for Stylish, the Firefox addon. Thought it might be useful to others.

Retrieve a list of all webpages on a site

This spiders the given site without downloading the HTML content. The resulting directory structure is then parsed to output a list of the URLs to url-list.txt. Note that this can take a long time to run and you make want to throttle the spidering so as to play nicely.

Generate random number with shuf

If you don't have seq or shuf, bash can be used.

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:

» all commands
» commands with 3 up-votes (commandlinefu3)
» commands with 10 up-votes (commandlinefu10)
» commands by twjolson