Copying a directory: cp -R source target

Removing a directory: rm -rf dir

—–

Mounting directory:

sudo mkdir /media/www
sudo mount //server/www /media/www

In /etc/fstab:

//server/www /media/www smb defaults 0 0

In /etc/hosts: 192.168.0.1 server

Using cifs with username and password in .smbcredentials:

//server/www    /media/www cifs   credentials=/root/.smbcredentials,iocharset=utf8 0 0

Ntfs-3g example usage:

/dev/sda2 /media/disk ntfs-3g defaults,nls=utf8,umask=007,gid=46 0 1

Reloading fstab: mount -a
—–

Compress/Decompress:

tar -cjf backup.tar.bz2 directory
tar -xjf backup.tar.bz2

tar -cvf tarname directory/
gzip tarname.tar
tar -xzvf tarname.tar.gz

Uncompress gz: tar -zxvf file.tar.gz

Uncompress zip: unzip file.zip

—–

Restart System / Apache / PostgreSQL / MySQL

shutdown -r now
sudo /etc/init.d/apache2 restart
sudo /etc/init.d/postgresql-8.2 restart
sudo /etc/init.d/mysql restart

—–

IP:

ifconfig / iwconfig
ip addr show
ip route

—–

Restart X-Server: Ctrl-Alt-BackSpace

—–

Linking:

ln -s target/path name

—–

All services: ps aux
Filtered services: ps aux | grep servicename

Search the whole file system: find / -name filename

Copy dir: cp -r dir/* dest/dir

Example /etc/network/interfaces:

auto lo
iface lo inet loopback
iface eth0 inet dhcp
address 192.168.1.22
netmask 255.255.255.0
gateway 192.168.1.254

auto eth0

Network info: sudo ifconfig

VI: ESC to get into command mode. In command mode use i to insert text, ESC to get back to command mode. Get out and save by typing :wq.

——

Mass find replace

——

General hardware info: lspci

——

My current /etc/hosts file:

127.0.0.1	localhost
127.0.1.1	henrik-desktop
192.168.0.1	server
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts

——

Location of Grub menu file: /boot/grub/menu.lst

——
find /home -name ‘*.avi’

chmod 777 folder

——

Shutting down / restarting:

sudo shutdown -P now

sudo reboot

——

Email:

Deleting the whole Postfix queue: postsuper -d ALL

Check how many mails in queue: mailq | tail -n 1

——

Checking folder info: du -hs dir

Checking Ubuntu version: lsb_release -a

Checking Kernel version: uname -r

Vacuuming Firefox database:

3.0.*
for f in ~/.mozilla/firefox/*/*.sqlite; do sqlite3 $f 'VACUUM;'; done
3.5.*
for f in ~/.mozilla/firefox-3.5/*/*.sqlite; do sqlite3 $f 'VACUUM;'; done

——

Pushing keys to remote server to be able to ssh without entering password all the time:

ssh-keygen -t dsa (accept all the defaults)
cat ~/.ssh/id_dsa.pub | ssh root@domain.com 'mkdir .ssh; cd .ssh; cat >> authorized_keys; chmod 600 authorized_keys'

Note: root@domain.com, it needs to be replaced with the server info in question and step 1 is only needed once. If you do it again and use default values you will overwrite your existing keys, not good.

Killing a process by name, 4 different methods from how to geek, I added the last one which will kill the process no matter what:

kill $(pgrep irssi) 
killall -v irssi
pkill irssi
kill `ps -ef | grep irssi | grep -v grep | awk ‘{print $2}’`
killall -9 -v irssi

Listing all big files / folders:

find . -type f -size +10000k -exec ls -lh {} \; | awk '{ print $8 ": " $5 }'

Getting my twitter timeline with CURL and saving it to twitter.xml with a 60 second timeout.

curl -u hsarvell:password -m 60 -o twitter.xml http://twitter.com/statuses/friends_timeline.xml

Dumping MySQL database:

mysqldump --databases dbname > /some/folder/dbname.sql
or verbose:
mysqldump databasename tablename --user userid --password > /some/folder/dbname.sql
bzip2 dbname.sql

Importing a dumped MySQL database with the file being encoded in utf8: 

mysql -u username -p --default_character_set utf8 dbase < file.sql

Printing computer specs (as root): lshw -html > specs.html

Turning off touchpad: synclient TouchpadOff=1

Compiling 32bit binaries on a 64bit system:
1.) sudo apt-get install gcc-multilib libc6-i386
2.) Use the -m32 flag.

Checking which ports are busy and what’s running behind them:
sudo apt-get install nmap
nmap -p 1-65535 -sV 127.0.0.1

Checking if any process is using port 80: netstat -anl | grep :80

Short note on how to setup new mail / change password on existing mail with Postfix and Courier:

cd /etc/postfix
nano access
nano virtual
cd virtual_domains
nano domain.com
cd /etc/courier/userdb
nano domain.com (add a hash for a password you already know)
cd /usr/lib/courier
perl makeuserdb
/etc/init.d/postfix restart

Adding a directory to your path, nano ~/.bashrc and:

PATH=$PATH:/opt/clojure
export PATH

What is my ip from the shell: wget -qO- whatismyip.org

——-

Undoing an arbitrary Mercurial commit:

hg log -l 10 -v
hg backout –merge -m ‘get back userinfo’ 516

The first line shows a verbose log so you can get at the changeset you want to undo by way of id, the second line will undo the change, in this case the changeset with id 516.

——-

Removing passphrase from ssl key: openssl rsa -in server.key -out server2.key

——-

Recovering files:

grep -a -B 25 -A 100 ’some string in the file’ /dev/sda1 > results.txt

Where 25 is the amount of lines before the match to output, 100 after and /dev/sda1 is the partition the file resided on, original here.