function zsh_stats() {
    fc -l 1 | awk '{CMD[$2]++;count++;}END { for (a in CMD)print CMD[a] " " CMD[a]/count*100 "% " a;}' | grep -v "./" | column -c3 -s " " -t | sort -nr | nl |  head -n20
  }
  
  function uninstall_oh_my_zsh() {
    env ZSH=$ZSH /bin/sh $ZSH/tools/uninstall.sh
  }
  
  function upgrade_oh_my_zsh() {
    env ZSH=$ZSH /bin/sh $ZSH/tools/upgrade.sh
  }
  
  function take() {
    mkdir -p $1
    cd $1
  }
  
  #
  # Get the value of an alias.
  #
  # Arguments:
  #    1. alias - The alias to get its value from
  # STDOUT:
  #    The value of alias $1 (if it has one).
  # Return value:
  #    0 if the alias was found,
  #    1 if it does not exist
  #
  function alias_value() {
      alias "$1" | sed "s/^$1='\(.*\)'$/\1/"
      test $(alias "$1")
  }
  
  #
  # Try to get the value of an alias,
  # otherwise return the input.
  #
  # Arguments:
  #    1. alias - The alias to get its value from
  # STDOUT:
  #    The value of alias $1, or $1 if there is no alias $1.
  # Return value:
  #    Always 0
  #
  function try_alias_value() {
      alias_value "$1" || echo "$1"
  }
  
  #
  # Set variable "$1" to default value "$2" if "$1" is not yet defined.
  #
  # Arguments:
  #    1. name - The variable to set
  #    2. val  - The default value 
  # Return value:
  #    0 if the variable exists, 3 if it was set
  #
  function default() {
      test `typeset +m "$1"` && return 0
      typeset -g "$1"="$2"   && return 3
  }
  
  #
  # Set enviroment variable "$1" to default value "$2" if "$1" is not yet defined.
  #
  # Arguments:
  #    1. name - The env variable to set
  #    2. val  - The default value 
  # Return value:
  #    0 if the env variable exists, 3 if it was set
  #
  function env_default() {
      env | grep -q "^$1=" && return 0 
      export "$1=$2"       && return 3
  }