Useful Tiny Bash Functions

Super nerd people spend most of their time in CLI. As long as we use terminal for our needs, we can also unlock new features from it by appending some codes in bashrc file. Here are some examples which we can use.

History auto-completion (type sudo and press up-arrow key, history includes sudo will come up)

bind '"\e[A": history-search-backward'
bind '"\e[B": history-search-forward'

Countdown timer

function countdown(){
  date1=$((`date +%s` + $1)); 
  while [ "$date1" -ne `date +%s` ];
    do echo -ne "$(date -u --date @$(($date1 - `date +%s`)) +%H:%M:%S)\r";
    sleep 0.1
  done
}

Stopwatch

function stopwatch(){
  date1=`date +%s`; 
  while true; 
    do echo -ne "$(date -u --date @$((`date +%s` - $date1)) +%H:%M:%S)\r"; 
    sleep 0.1
  done
}

Alarm

alarm() {
sleep $1; 
while :; 
  do paplay /usr/share/sounds/freedesktop/stereo/alarm-clock-elapsed.oga; 
  read -t 0.01 -n 1; 
  if [ $? = 0 ]; then 
    break; 
  fi; 
  done
}

Random commands from commandlinefu.com

cfu () { 
  wget -qO - http://www.commandlinefu.com/commands/random/plaintext | \
  sed -n '/AD/!p' | sed -n '/commandlinefu.com/!p' | tee ~/.cfu; 
  read -p "Do you want to save? (y/n) " ans
  if [ $ans == y ]; then
    cat ~/.cfu >> ~/Useful_Commands;
  fi
}