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ssh hostchange know_host improver

If you work in an environment, where some ssh hosts change regularly this might be handy...
This is sample output - yours may be different.
-1

sshostnew () {sed -i "$1d" $HOME/.ssh/known_hosts ; }

_john · 2011-11-07 10:33:04 11
Create a false directory structure for testing your commands

You could avoid xargs and sed in this case (shorter command and less forking): At least bash and zsh have some mighty string modifiers. I would also suggest using find with exec option to get more flexibility. You may leave out or include "special" file for example.
This is sample output - yours may be different.
0

for i in /usr/bin/* ;do touch ${i##*/}; done

_john · 2011-10-20 12:38:45 4
Install 4 new package files

after kernel build with make deb-pkg, I like to install the 4 newest packages that exist in the directory. Beware: might be fewer for you....
This is sample output - yours may be different.
0

sudo dpkg -i `ls -tr *.deb | tail -n4`

_john · 2011-10-09 14:20:11 4
Number of CPU's in a system

All Linux Systems I try also have an empty line per cpu in /proc/cpuinfo... little shorter then... Show Sample Output
This is sample output - yours may be different.
```
4
```
0

grep -c '^$' /proc/cpuinfo

_john · 2011-10-09 14:05:14 4
Remove all unused kernels with apt-get

since awk was already there one can use it instead of the 2 greps. might not be faster, but fast enough
This is sample output - yours may be different.
0

apt-get remove $(dpkg -l | awk "/^ii linux-(image|headers)/ && ! /`uname -r`/ {print \$2}")

_john · 2011-10-09 13:58:47 5

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list block devices

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

show framebuffer console modes to use in grub vga option

look at /boot/grub/menu.lst for somethig like: ## additional options to use with the default boot option, but not with the ## alternatives ## e.g. defoptions=vga=791 resume=/dev/hda5 ## defoptions=vga=795 # defoptions=vga=873 ## altoption boot targets option ## multiple altoptions lines are allowed ## e.g. altoptions=(extra menu suffix) extra boot options ## altoptions=(recovery) single # altoptions=(verbose mode) vga=775 debug # altoptions=(console mode) vga=ask # altoptions=(graphic mode) quiet splash # altoptions=(recovery mode) single vga=(decimal value) is framebuffer mode

Separates each frame of a animated gif file to a counted file, then appends the frames together into one sheet file. Useful for making sprite sheets for games.

requires imagemagick

Create a mirror of a local folder, on a remote server

Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

List the size (in human readable form) of all sub folders from the current location

Sorted in human readable format.

Silently Execute a Shell Script that runs in the background and won't die on HUP/logout

This command runs your shell script in the background with no output of any kind, and it will remain running even after you logout.

continuously check size of files or directories

Create a 5 MB blank file

Useful for testing purposes

Extract tar content without leading parent directory

If archive has leading directory level same as archive name and you want to strip it, this command is for you.

Rename files in batch

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Commands by _john (5)

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