Commands by xakon (6)

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Umount only the NFS related to 'string'
Sometimes, you have a lot of NFS in the server and you can't or shouldn't use umount -a. Whis this command, you only umount the fs related to the 'string'

hanukkah colored bash prompt
blue and yellow colored bash prompt for a Hanukkah celebration on your box

List top 10 files in filesystem or mount point bigger than 200MB
Specify the size in bytes using the 'c' option for the -size flag. The + sign reads as "bigger than". Then execute du on the list; sort in reverse mode and show the first 10 occurrences.

Quick find function
A function that allows you to perform a case-insensitive search in the current directory, and directories in the current directory (but no further), for files containing the first argument anywhere in their names.

Redirect incoming traffic to SSH, from a port of your choosing
Stuck behind a restrictive firewall at work, but really jonesing to putty home to your linux box for some colossal cave? Goodness knows I was...but the firewall at work blocked all outbound connections except for ports 80 and 443. (Those were wide open for outbound connections.) So now I putty over port 443 and have my linux box redirect it to port 22 (the SSH port) before it routes it internally. So, my specific command would be: $iptables -t nat -A PREROUTING -p tcp --dport 443 -j REDIRECT --to-ports 22 Note that I use -A to append this command to the end of the chain. You could replace that with -I to insert it at the beginning (or at a specific rulenum). My linux box is running slackware, with a kernel from circa 2001. Hopefully the mechanics of iptables haven't changed since then. The command is untested under any other distros or less outdated kernels. Of course, the command should be easy enough to adapt to whatever service on your linux box you're trying to reach by changing the numbers (and possibly changing tcp to udp, or whatever). Between putty and psftp, however, I'm good to go for hours of time-killing.

Remote backups with tar over ssh
Execute it from the source host, where the source files you wish backup resides. With the minus '-' the tar command deliver the compressed output to the standar output and, trough over the ssh session to the remote host. On the other hand the backup host will be receive the stream and read it from the standar input sending it to the /path/to/backup/backupfile.tar.bz2

Scrollable Colorized Long Listing - Hidden Files Sorted Last
To sort hidden files first, simply switch the two inner `ls` commands. I have this aliased to `dira` `dir` is aliased to the simpler version with no hidden files: $ ls -l --color=always | less -R

Match a URL
For the record: I didn't build this. Just shared what I found that worked. Apologies to the original author! I decided I should fix the case where http://example.com is not matched for the next time I need this. So I read rfc1035 and formalized the host name regex. If anyone finds any more holes, please comment.

get a desktop notification from the terminal
tired of switching to the console to check if some command has finished yet? if notify-send does not work on your box try this one... e.g. rsync -av -e /usr/bin/lsh $HOME slowconnection.bar:/mnt/backup ; z (now fire up X, do something useful, get notified if this stuff has finished).

count the number of specific characters in a file or text stream
In this example, the command will recursively find files (-type f) under /some/path, where the path ends in .mp3, case insensitive (-iregex). It will then output a single line of output (-print0), with results terminated by a the null character (octal 000). Suitable for piping to xargs -0. This type of output avoids issues with garbage in paths, like unclosed quotes. The tr command then strips away everything but the null chars, finally piping to wc -c, to get a character count. I have found this very useful, to verify one is getting the right number of before you actually process the results through xargs or similar. Yes, one can issue the find without the -print0 and use wc -l, however if you want to be 1000% sure your find command is giving you the expected number of results, this is a simple way to check. The approach can be made in to a function and then included in .bashrc or similar. e.g. $ count_chars() { tr -d -c "$1" | wc -c; } In this form it provides a versatile character counter of text streams :)


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