Easily edit your /etc/host file

host-manager

#!/bin/bash

_hosts() {
    hostfile="/etc/hosts"
    addusage="Usage: `basename $0` --add address host"
    remusage="Usage: `basename $0` --remove host"

    case "$1" in
    --add)
      if [ $# -eq 3 ]; then
        if [[ -n $(grep "^$2.*[^A-Za-z0-9\.]$3$" ${hostfile}) ]]; then
          echo "Duplicate address/host combination, ${hostfile} unchanged."
        else
          printf "$2\t$3\n" >> ${hostfile}
        fi
      else
        echo $addusage;
      fi
      ;;
    --remove)
      if [ $# -eq 2 ]; then
        sudo sh -c "sed -i '' -e 's/^[^#].*[^A-Za-z0-9\.]$2$//g' -e '/^$/ d' ${hostfile}"
      else
        echo $remusage;
      fi
      ;;
    *)
      echo $addusage;
      echo $remusage;
    esac
}

alias hosts=_hosts

usage

hosts --add 127.0.0.1 myapp
hosts --remove myapp