Terminal

Useful Commands

System Control

reboot
poweroff

Disk

# check disk size
df -h

# check the directory size under current path.
du -h

# check partitions
cat /proc/partitions
lshw -C disk

# partition disk
fdisk /dev/sda
 : n
 : w

# gpt partition disk (fdisk do not support gpt)
parted /dev/sda
 : mklabel gpt
 : unit mb
 : p              <-- looks for size of drive in MB
 : mkpart primary 0 <insert size of drive in MB>
 : quit

# format disk (after you use fdisk partition the hardware disk)
mkfs.ext4 /dev/sda1

# mount device
mkdir /mnt/db
mount /dev/sda1 /mnt/db

#unmount drive
umount /mnt/db

Raid

# check the raid device status
cat /proc/scsi/rr26xx/6

FTP

# login
lftp user:passward@server-name

# upload file
put filepath

# upload directory
mirror -R dirpath

Symbolic Link

# symlink /foo/bar/ as foobar                                            
ln -s /foo/bar/ foobar                                                   

# list all files, the symlinked file will display as /foo/bar/ -> foobar 
ls -la                                                                   

# delete a symlinked file.                                               
unlink foobar                                                            
# or you can use rm,                                                     
# NOTE: don't use rm foobar/                                             
rm foobar

Show Current Directory Path

# show current directory path
pwd

# get current directory value
$PWD

# copy current directory to clipboard
pwd | pbcopy # NOTE: you can use pbpaste to paste content from clipboard

Compress/Uncompress files

# compress to .tar
tar -cvf file.tar inputfile1 inputfile2

# uncompress .tar
tar -xvf file.tar

# compress to .tar.gz
tar -cvzf file.tar.gz inputfile1 inputfile2

# uncompress .tar.gz
tar -xvzf file.tar.gz

Synchronize Two Folders

rsync --delete -alzvv SRC_FOLDER TARGET_FOLDER
rsync --delete -alzvv $HOME/.kde/ /mnt/backups/kde
rsync --delete -alzvv $HOME/Mail/ /mnt/backups/mail

Package install

# install redhat pacakge
rpm -i foobar.rpm

# convert rpm to deb
alien foobar.rpm

# install debian pacakge
dpkg -i foobar.deb