# Directory
pwd                 # Current Dir
cd                   # Home
cd ..                # Up
cd /                 # Root
cd /home          # Home
cd /home/root   # User Dir
cd /tmp            # /tmp
cd ~                # Home

# File List
ls
ls --full-time
ls -1
ls -als
ls -ls

# Search
find / -iname FILE_NAME
find / -size +10000k
grep -r PATTERN dir
grep PATTERN FILES

# System
date
hostname
hostname -i
uname
uptime
whoami

# User
id
last
who

# Network
ifconfig
netstat
ping google.com -c 3        # 3 seconds

# File Permission
chmod 755 /tmp/FILE_NAME
chmod 766 /tmp/FILE_NAME
chmod 777 /tmp/FILE_NAME

# Disk usage
df -h
