commandlinefu.com is the place to record those command-line gems that you return to again and again.
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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.
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,…):
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Useful when you're trying to unmount a volume and other sticky situations where a rogue process is annoying the hell out of you.
Curious about differences between /bin, /usr/bin, and /usr/local/bin? What should be in the /sbin dir? Try this command to find out.
Tested against Red Hat & OS X
While I love gpg and truecrypt there's some times when you just want to edit a file and not worry about keys or having to deal needing extra software on hand. Thus, you can use vim's encrypted file format.
For more info on vim's encrypted files visit: http://www.vim.org/htmldoc/editing.html#encryption
Using awk, find duplicates in a file without sorting, which reorders the contents. awk will not reorder them, and still find and remove duplicates which you can then redirect into another file.
This command will start a simple SMTP server listening on port 1025 of localhost. This server simply prints to standard output all email headers and the email body.
/usr/sbin/ab2 -f TLS1 -S -n 1000 -c 100 -t 2 http://www.google.com/
is the same as
/usr/sbin/ab2 -f TLS1 -S -n 1000 -c 100 -t 2 http://www.commandlinefu.com/
This dup finder saves time by comparing size first, then md5sum, it doesn't delete anything, just lists them.
As an alternative to using an additional grep -v grep you can use a simple regular expression in the search pattern (first letter is something out of the single letter list ;-)) to drop the grep command itself.
translate <phrase> <source-language> <output-language>
translate hello en es
See this for a list of language codes:
Pressing ESC then * will insert in the command line the results of the autocompletion.
It's hard to explain but if you look the sample output or do
echo ESC *
you will understand quickly.
By the way, few reminders about ESC :
- Hold ESC does the same thing as tab tab
- 'ESC .' inserts the last argument of last command (can be done many times in order to get the last argument of all previous commands)
Replace and accordingly.
If you use Mac OS X or some other *nix variant that doesn't come with ssh-copy-id, this one-liner will allow you to add your public key to a remote machine so you can subsequently ssh to that machine without a password.
defines a handy function for quick calculations from cli.
This is the result of a several week venture without X. I found myself totally happy without X (and by extension without flash) and was able to do just about anything but watch YouTube videos... so this a the solution I came up with for that. I am sure this can be done better but this does indeed work... and tends to work far better than YouTube's ghetto proprietary flash player ;-)
Replace $i with any YouTube ID you want and this will scrape the site for the _real_ URL to the full quality .FLV file on Youtube's server and will then will hand that over to mplayer (or vlc or whatever you want) to be streamed.
In some browsers you can replace $i with just a % or put this in a shell script so all YouTube IDs can be handed directly off to your media player of choice for true streaming without the need for Flash or a downloader like clive. (I do however fully recommend clive if you wish to archive videos instead of streaming them)
If any interest is shown I would be more than happy to provide similar commands for other sites. Most streaming flash players use similar logic to YouTube.
Edit: 05/03/2011 -
Updated line to work with current YouTube. It could be a lot prettier but I will probably follow up with another update when I figure out how to get rid of that pesky Grep. Sed should take that syntax... but it doesn't.
Original (no longer working) command:
mplayer -fs $(echo "http://youtube.com/get_video.php?$(curl -s $youtube_url | sed -n "/watch_fullscreen/s;.*\(video_id.\+\)&title.*;\1;p")")
Prints a graphical directory tree from your current directory
Many like to use 'dd' for creating CD/DVD iso images. This is bad. Very bad. The reason this is, is 'dd' doesn't have any built-in error checking. So, you don't know if you got all the bits or not. As such, it is not the right tool for the job. Instead, 'reaom' (read optical media) from the wodim package is what you should be using. It has built-in error checking. Similarly, if you want to burn your newly creating ISO, stay away from 'dd', and use:
wodim -v -eject /path/to/image.iso
Similarly, if you want to print from 10 to the end of line you can use: sed -n '10,$p' filename
This is especially useful if you are dealing with a large file. Sometimes you just want to extract a sample without opening the entire file.
Credit goes to wbx & robert at the comments section of http://www.commandlinefu.com/commands/view/348/get-line1000-from-text.#comment
pv allows a user to see the progress of data through a pipeline, by giving information such as time elapsed, percentage completed (with progress bar), current throughput rate, total data transferred, and ETA. (man pv)