Not so frequent command line hacks

• Read which processes are writing to the hard drive
  
  # echo 1 | sudo tee /proc/sys/vm/block_dump
  
  wait few seconds
  
  # echo 0 | sudo tee /proc/sys/vm/block_dump
  
  # dmesg | grep WRITE
  
  
• Detect service and server versions using nmap:
  
  # nmap -A -T4 -F 192.168.1.1
  
  
• Print the detailed statistics of transferred bytes by the firewall rules
  
  # sudo iptables -L -nv
  
  
• Convert the bit rate of an MP3
  
  # lame -b 128 input.mp3 output.mp3
  
  
• Setup wireless network from command line:
  
  # sudo iwconfig wlan0 essid MY_AP_ESSID
  # sudo iwconfig wlan0 key "12371272BCBCBABC1212"
  # sudo dhclient wlan0
  
  where wlan0 is the ID of network device.
  
  
• Which process is accessing the CDROM
  
  # lsof -n | grep /media/cdrom
  
  
• Convert DOS end of line to UNIX end of line
  
  # sed -e 's/\r$//' inputfile > outputfile
  
  or
  
  # tr '\r' '\n' < inputfile > outputfile
  
  
• Get the size of a directory
  
  # du -sh /home/blabla
  
  
• Change MAC address of a network interface
  
  # sudo ifconfig wlan0 hw ether AA:AA:BB:BB:CC:DD
  
  
• Change your password in a non-interactive shell (PHP, Python web shells). Edit and paste these lines in to your shell:
  
  passwd <<+++
  oldpasswd
  newpasswd
  newpasswd
  +++