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Tips/Tricks

Tips/Tricks

Multiple X

Start multiple X sessions:

startx – :1

display

Rename Files

for file in `ls .`; do mv “$file” “${file/old/new}”; done

rename

Transfer files

Transfer files (insecurely)

Remote machine

nc -l -p 1234 | uncompress -c | tar xvfp -

Local machine

tar cfp - /some/dir | compress -c | nc -w 3 [destination] 1234

Backup Mysql

2 2 * * * root mysqldump -u root -pPASSWORD --all-databases | gzip > /mnt/disk2/database_`data ' %m-%d-%Y'`.sql.gz

mysql, backup

Execute the last command as root

$ sudo !!

Non-numeric permissions

Who

u — file owner
g — group member of
o — other
a — all (u, g, and o)

Permissions

r — read 
w — write 
x — execute

Actions

+ — adds the permission
- — removes the permission
= — makes it the only permission

Find and Replace

grep -lr -e '<string2change>' * | xargs sed -i 's/<string2change>/<new-string>/g'

find

VPNC resolve.conf workaround

*/10 * * * * root if [ -e /etc/resolvconf/run/interface/tun0 -a “`pidof vpnc`” == ”” ] ; then /sbin/resolvconf -d tun0; fi

VPNC, DNS

utmpdump

View login activity 
utmpdump /var/log/wtmp

utmpdump, login

Unonstrain windows to the top of the screen

gconftool-2 --set /apps/compiz/plugins/move/allscreens/options/constrain_y --type bool 0

gnome, alt, window

Find all files in current directory and sort by size

Find all files in current directory and sort by size – I put this in my .bashrc

dfn ()
{
du --all --max-depth=1 $@ | sort -n | awk '{if ($1>1048576) {print int($1/1048576)"G",$2}else if ($1>1024) {print int($1/1024)"M",$2} else {print $1"K",$2}}'
}

du, find, files

Find a 4 character string in line occuring 20 characters in and following "topic"

Find a 4 character string in line occuring 20 characters in and following “topic”

cat file.txt |grep -e "topic"|sed 's/^.\{19\}\(.\{4\}\)\(.*\)/\1/'

sed, parse, text

winmail.dat

Huh? winmail.dat

ytnef -f . winmail.dat

attachment, email

Reset frozen system

(Alt+SysRq)+R+S+E+I+U+B

SysRq, reset, reboot

Directory Tree from Bash

ls -R | grep ":$" | sed -e 's/:$//' -e 's/[^-][^\/]*\//--/g' -e 's/^/ /' -e 's/-/|/'

list, tree, directory, sed, grep

Clone System

Clone system

On current box
  dpkg --get-selections > /tmp/dpkglist.txt

New Box. Don't forget to restore configs! (/etc /home ...)
  sudo dpkg --set-selections < /tmp/dpkglist.txt
  sudo apt-get -y update
  sudo apt-get dselect-upgrade

Debian, dpkg, clone

Display Useful Info From Cmd Line

notify-send

notify-send "Process Complete"

bash, notify

CentOS Items

DAG

http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.1-1.el5.rf.x86_64.rpm

rpm --import http://apt.sw.be/RPM-GPG-KEY.dag.txt

CentOS, RPMForge, RPM, packages, repos, yum

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