Commands by anapsix (5)

  • Display Spinner while waiting for some process to finish

    alternatively, run the spinner for 5 seconds: timeout 5 bash -c 'spinner=( Ooooo oOooo ooOoo oooOo ooooO oooOo ooOoo oOooo); while true; do for i in ${spinner[@]}; do for j in seq 0 ${#i}; do echo -en "\b\b"; done; echo -ne "${i}"; sleep 0.2; done; done' Show Sample Output


    2
    while kill -0 0; do timeout 5 bash -c 'spinner=( Ooooo oOooo ooOoo oooOo ooooO oooOo ooOoo oOooo); while true; do for i in ${spinner[@]}; do for _ in seq 0 ${#i}; do echo -en "\b\b"; done; echo -ne "${i}"; sleep 0.2; done; done'; done
    anapsix · 2015-05-07 19:13:08 2
  • get a random 0/1, use it for on/off, yes/no

    use it to add a random boolean switch to your script Show Sample Output


    4
    echo $[RANDOM % 2]
    anapsix · 2013-05-25 19:15:57 3
  • get a random number in bash

    use it to stagger cronjob or to get a random number increase the range by replacing 100 with your own max value Show Sample Output


    -2
    echo $[RANDOM % 100] # range 0-99
    anapsix · 2013-05-25 19:02:00 0
  • Check if system is 32bit or 64bit


    16
    arch
    anapsix · 2013-01-02 17:52:14 3
  • Find all active ip's in a subnet

    nmap for windows and other platforms is available on developer's site: http://nmap.org/download.html nmap is robust tool with many options and has various output modes - is the best (imho) tool out there.. from nmap 5.21 man page: -oN/-oX/-oS/-oG : Output scan in normal, XML, s| Show Sample Output


    6
    nmap -v -sP 192.168.0.0/16 10.0.0.0/8
    anapsix · 2010-07-14 19:53:02 0

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

leave a stale ssh session
When your ssh session hanged (probably due to some network issues) you can "kill" it by hitting those 3 keys instead of closing the entire terminal.

Show apps that use internet connection at the moment. (Multi-Language)
for one line per process: $ ss -p | cat for established sockets only: $ ss -p | grep STA for just process names: $ ss -p | cut -f2 -sd\" or $ ss -p | grep STA | cut -f2 -d\"

Create a DOS floppy image
mount with: mount -t msdos -o loop ./floppy.img /tmp/mnt

Securely destroy data (including whole hard disks)
GNU shred is provided by the coreutils package on most Linux distribution (meaning, you probably have it installed already), and is capable of wiping a device to DoD standards. You can give shred any file to destroy, be it your shell history or a block device file (/dev/hdX, for IDE hard drive X, for example). Shred will overwrite the target 25 times by default, but 3 is enough to prevent most recovery, and 7 passes is enough for the US Department of Defense. Use the -n flag to specify the number of passes, and man shred for even more secure erasing fun. Note that shredding your shell history may not be terribly effective on devices with journaling filesystems, RAID copies or snapshot copies, but if you're wiping a single disk, none of that is a concern. Also, it takes quite a while :)

share internet connection with only one network interface
the below command create a alias for share your internet connection with another. $ifconfig eth0:1 192.168.0.1/24 Its obviously necessary too activate the iptables post-routing and ip forwarding, as root: $modprobe iptable_nat $iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE $echo 1 > /proc/sys/net/ipv4/ip_forward Be sure that the alias 192.168.0.0/24 is not your active real ip range

print text in color red
eg: $printTextInColorRed foo bar foo bar [in red color]

Compress files found with find
tar options may change ;) c to compress into a tar file, z for gzip (j for bzip) man tar -print0 and -0t are usefull for names with spaces, \, etc.

Play musical notes from octave of middle C
Are there any creative pieces of music that can be created using beep and the shell? I'd love to hear it!

Convert mp3/wav file to asterisk ulaw for music on hold (moh)

Install pip with Proxy
Installs pip packages defining a proxy

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: