How can I shortern my command line prompt's current directory?

Question

I am using Ubuntu and I am tired of this long prompts in bash when I am working with some deep directory hierarchy. So, I would like to tweak my PS1 to shorten the working d

Answer 1

Another approach, still using sed and awk to generate the prompt. This will convert your $HOME directory into ~, show you your root directory, your lowest level (current directory), and its parent, separated by .. for each directory in between.

Inside of your .bashrc (or .bash_profile on OS X):

function generate_pwd {
  pwd | sed s.$HOME.~.g | awk -F"/" '
  BEGIN { ORS="/" }
  END {
  for (i=1; i<= NF; i++) {
      if ((i == 1 && $1 != "") || i == NF-1 || i == NF) {
        print $i
      }
      else if (i == 1 && $1 == "") {
        print "/"$2
        i++
      }
      else {
        print ".."
      }
    }
  }'
}
export PS1="\$(generate_pwd) -> "

The script uses awk's built in NF variable (number of fields) and positional variables ($1, $2 ...) to print each field (directory name) separated by the ORS variable (output record separator). It collapses the inner directories into .. in your prompt.

Example of it in use:

~/ -> cd Documents/
~/Documents/ -> cd scripts/
~/Documents/scripts/ -> cd test1/
~/../scripts/test1/ -> cd test2
~/../../test1/test2/ -> pwd
/Users/Brandon/Documents/scripts/test1/test2
~/../../test1/test2/ -> cd test3/
~/../../../test2/test3/ -> cd test4/
~/../../../../test3/test4/ -> pwd
/Users/Brandon/Documents/scripts/test1/test2/test3/test4
~/../../../../test3/test4/ -> cd /usr/
/usr/ -> cd local/
/usr/local/ -> cd etc/
/usr/local/etc/ -> cd openssl/
/usr/../etc/openssl/ -> cd private/
/usr/../../openssl/private/ ->