Get canonical value of relative path from bash script

magic() {
    for p in "$@"; do
        [ -O "$p" -a -x "$p" ] && /bin/sh "$p"
    done
}

read 'man test' to see what the checks do.

Ok, I got curious, so here's one solution:

1. First, create a function using a slight tweak of William Pursell's answer to the SO question I link in my comment above.
2. Next, put that in your $PS1 as \$(function_name) in the appropriate place.

As an example:

short_pwd() {
    cwd=$(pwd | perl -F/ -ane 'print join( "/", map { $i++ < @F - 1 ?  substr $_,0,1 : $_ } @F)')
    echo -n $cwd
}
# later in your .bashrc
PS1="\u \$(short_pwd) \$ "

I'm hopeful that someone more skilled in Bash-scripting than I am can suggest ways to clean up the function, but this should give you some idea of how to use the output of another command (or Bash function) in a prompt. See also here: http://www.linux.org/docs/ldp/howto/Bash-Prompt-HOWTO/x279.html

Based on your comment, I looked again and realized that my solution needs to be double quoted. If you single-quote such a function, then it will not function at all.