Basic Linux Command

# show file/folder attribute
$ ls -l

# change file attribute
# 777 => 111,111,111 => rwx,rwx,rwx
# 531 => 101,011,001 => r-x,-wx,--x
$ chmod 777 file_or_folder_name


# see recent mounted drives
$ df
# human readable format
$ df -h


# mount a drive
# first create a mouning point folder, then mount
$ mkdir /media/folder_name
$ sudo mount -t auto /dev/sda6 /media/folder_name # or other name


# unmount a drive
$ sudo umount -t  auto /dev/sda6

# display currently active processes.
$ ps


# dispaly all running processes.
$ top

# get pid of a process
$ pidof process_name

# kill process
$ pkill mysqld
$ kill -SIGTERM pid