commandlinefu.com is the place to record those command-line gems that you return to again and again.
Delete that bloated snippets file you've been using and share your personal repository with the world. 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.
If you have a new feature suggestion or find a bug, please get in touch via http://commandlinefu.uservoice.com/
You can sign-in using OpenID credentials, or register a traditional username and password.
First-time OpenID users will be automatically assigned a username which can be changed after signing in.
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
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:
Seems obvious, but other seemingly simple ways to use it don't work:
echo !whammy
and
echo "!whammy"
both output:
-bash: !whammy: event not found
and this:
echo "\!whammy"
outputs:
\!whammy
with the slash :(
you can also do any combinations of quotes for a complex string:
echo "It's great to be able to use a bang ("'!'") in a command"'!'
outputs:
It's great to be able to use a bang (!) in a command!
This command is great for dumping your history so that when you're working on a system that is under a shared account, you can keep others from reviewing your history file. I use this when I'm just visiting a system to diagnose a problem, or to make a quick fix.
Change /dev/sda with the Disk or partition you want to back-up
To restore use:
dd if=~/backup-disk-YY-MM-DD.img of=/dev/sda
Once again change /dev/sda accordingly
Source: http://www.go2linux.org/linux/2010/09/small-tip-back-disks-clone-hard-disk-773
This is useful when you got a reserved IP address like 192.168.0.100 and want to find out what IP address is used to access the Internet. You have to know a server with 'efingerd -n' configured, like www.linuxbanks.cn as above.
Other method to find out this information are for example access www.tell-my-ip.com and grep the output. The finger method have the advantage that it is easy to deploy a service like www.tell-my-ip.com, as you only need to get efingerd installed.
Display the machine "hardware name" 32 or 64 bit.
"x86_64" is shown on 64 bit machines
"i686" is typically shown on 32 bit machines (although, you might also see "i386" or "i586" on older Linuxen).
On other "unix-like" systems, other hardware names will be displayed.
For example, on AIX, "uname -m" gives the "machine sequence number".
For whatever reason, IBM decided that "uname -M" would give the machine type and model.
(ref: http://www.ibm.com/developerworks/aix/library/au-aix-systemid.html )
On Sun Solaris, "uname -m" can be used to determine the chip type and "isainfo -v" will reveal
if the kernel is 64 or 32 bit.
(ref: http://www.ibiblio.org/pub/packages/solaris/sparc/html/32.and.64.bit.packages.html )
A more reliable way to determine "64-bit ness" across different Unix type systems is to compile the following simple C program:
cat <<eeooff > bits.c
/*
* program bits.c
* purpose Display "32" or "64" according to machine type
* written January 2013
* reference http://www.unix.org/whitepapers/64bit.html
*/
/* hmm, curious that angle-brackets removed by commandlinefu.com data input processing? */
#include "/usr/include/stdio.h"
long lv = 0xFFFFFFFF;
main ( ) {
printf("%2d\n",(lv < 0)?32:64);
}
eeooff
Compile and run thusly: cc -o bits bits.c; ./bits
Can pipe to tail or change the awk for for file size, groups, users, etc.
Looks like you're stuck with sed if your ls doesn't have a -Q option.
With counter format [001, 002, ..., 999] , nice with pictures or wallpapers collections.
no external commands, but can only do 0-99, not 1-100, so we adjust it later
Did some research and found the previous command wrong, we don't kill a zombie but its parent. Just made some modifcation to khashmeshab's command.