Commands by px (3)

  • This one-liner will use strace to attach to all of the currently running apache processes output and piped from the initial "ps auxw" command into some awk. Show Sample Output


    7
    ps auxw | grep sbin/apache | awk '{print"-p " $2}' | xargs strace
    px · 2011-03-14 21:45:22 7
  • This one-liner is for cron jobs that need to provide some basic information about a filesystem and the time it takes to complete the operation. You can swap out the di command for df or du if that's your thing. The |& redirections the stderr and stdout to the mail command. How to configure the variables. TOFSCK=/path/to/mount FSCKDEV=/dev/path/device or FSCKDEV=`grep $TOFSCK /proc/mounts | cut -f1 -d" "` MAILSUB="weekly file system check $TOFSCK " Show Sample Output


    1
    ( di $TOFSCK -h ; /bin/umount $TOFSCK ; time /sbin/e2fsck -y -f -v $FSCKDEV ; /bin/mount $TOFSCK ) |& /bin/mail $MAILTO -s "$MAILSUB"
    px · 2010-10-24 00:35:23 1
  • Use GNU/screen as a terminal emulator for anything serial console related. screen /dev/tty eg. screen /dev/ttyS0 9600 MacOSX: http://www.macosxhints.com/article.php?story=20061109133825654 Cheat Sheet: http://www.catonmat.net/blog/screen-terminal-emulator-cheat-sheet/ Show Sample Output


    10
    screen /dev/tty<device> 9600
    px · 2010-07-20 09:12:13 3

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find duplicate processes
This command will allow to search for duplicate processes and sort them by their run count. Note that if there are same processes run by different users you'll see only one user in the result line, so you'll need to do: $ ps aux | grep to see all users that run this command.

Cryptographically secure 32-bit RNG in strict ZSH
ZSH ships a couple random number generators via the $RANDOM environment variable and rand48() via zsh/mathfunc, but neither are cryptographically secure. This code produces a 32-bit random number suitable for cryptography. It's only dependency is /dev/urandom and it does not rely on any shell commands or 3rd party utilities. It assumes ZSH was compiled with 64-bit integer support.

Serve current directory tree at http://$HOSTNAME:8000/

Check whether IPv6 is enabled
Checks whether IPv6 is enabled system-wide by reading from procfs.

Advanced LS Output using Find for Formatted/Sortable File Stat info
I love this function because it tells me everything I want to know about files, more than stat, more than ls. It's very useful and infinitely expandable. $ find $PWD -maxdepth 1 -printf '%.5m %10M %#9u:%-9g %#5U:%-5G [%AD | %TD | %CD] [%Y] %p\n' | sort -rgbS 50% 00761 drwxrw---x askapache:askapache 777:666 [06/10/10 | 06/10/10 | 06/10/10] [d] /web/cg/tmp The key is: # -printf '%.5m %10M %#9u:%-9g %#5U:%-5G [%AD | %TD | %CD] [%Y] %p\n' which believe it or not took me hundreds of tweaking before I was happy with the output. You can easily use this within a function to do whatever you want.. This simple function works recursively if you call it with -r as an argument, and sorts by file permissions. $ lsl(){ O="-maxdepth 1";sed -n '/-r/!Q1'

Fork Bomb for Windows
Quick and dirty forkbomb for all flavors of windows Do not use in production. Replace start with a command of your choice, this will just open a new command prompt and is pretty tricky to stop once started

Random line from bash.org (funny IRC quotes)
bash.org is a collection of funny quotes from IRC. WARNING: some of the quotes contain "adult" jokes... may be embarrassing if your boss sees them... Thanks to Chen for the idea and initial version! This script downloads a page with random quotes, filters the html to retrieve just one liners quotes and outputs the first one. Just barely under the required 255 chars :) Improvment: You can replace the head -1 at the end by: $awk 'length($0)>0 {printf( $0 "\n%%\n" )}' > bash_quotes.txt which will separate the quotes with a "%" and place it in the file. and then: $strfile bash_quotes.txt which will make the file ready for the fortune command and then you can: $fortune bash_quotes.txt which will give you a random quote from those in the downloaded file. I download a file periodically and then use the fortune in .bashrc so I see a funny quote every time I open a terminal.

list block devices
Shows all block devices in a tree with descruptions of what they are.

Find Out My Linux Distribution Name and Version

Check to make sure the whois nameservers match the nameserver records from the nameservers themselves
Change the $domain variable to whichever domain you wish to query. Works with the majority of whois info; for some that won't, you may have to compromise: domain=google.com; for a in $(whois $domain | grep "Domain servers in listed order:" --after 3 | grep -v "Domain servers in listed order:"); do echo ">>> Nameservers for $domain from $a


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