Shell – How to tell if I’m actually in a symlink location from command line

With any POSIX implementation of cd, you can use the -P option to do this.

$ help cd
...
    -P      use the physical directory structure without following symbolic links
...

You can see it in action here:

$ mkdir foo
$ ln -s foo bar
$ cd -P bar
$ pwd
/tmp/tmp.WkupF2Ucuh/foo

If you want this to be the default behaviour, you can either create an alias for cd, like so:

alias cd='cd -P'

...or use set -o physical. For tcsh, the equivalent command is set symlinks=chase.

You could use tab completion. By default on many Linux distributions, bash is set up so that when you hit the [TAB] key, you're given a list of possible matches, or if there's just one match, it's all filled out. For cd, this is normally a list of subdirectories of the current working directory. You could overwrite that, but I suggest instead making an alias, like jd for "jump directory":

alias jd=cd

and then, defining the "bookmarks" you want as completions for jd. Look at the bash man page for a lot more options (including auto-generating the results on the fly from a command or function), but the easiest way is just a list of words, with -W:

complete -W "/srv/www ~/tmp ~/work" jd

Now, type jd and hit [TAB], and you'll see your "bookmarks". Type any ambiguous part, and then hit [TAB] to complete. (In the above, the ~s expand to my home directory, so the first [TAB] gives me a /, and if I hit w and [TAB] again, /srv/www is filled out.)

Of course, put this in ~/.bash_profile to make it persist.

Or, we can take this to the next level. Make a directory ~/.shortcuts — starting with a dot, it'll be hidden and not muss up your nice clean home directory — and fill that with symlinks to your desired directories. Then, put this in your ~/.bash_profile:

_list_shortcuts() 
{ 
    COMPREPLY=($( compgen -W "$( ls ~/.shortcuts )" -- ${COMP_WORDS[COMP_CWORD]} ))
}
jd()
{
    cd -P ~/.shortcuts/$1
}
complete -F _list_shortcuts jd

This defines a slightly more complicated completion in the fuction _list_shortcuts to build the list of names, and makes jd be a function rather than a simple alias, since we want it to act differently from just cd. The -P flag to cd makes it resolve the symlinks, so everything becomes transparent magic. Your shortcut names don't even have to match the targets.

So:

$ ls -l ~/.shortcuts/
total 0
lrwxrwxrwx. 1 mattdm mattdm 16 Dec 17 19:44 tmp -> /home/mattdm/tmp
lrwxrwxrwx. 1 mattdm mattdm 17 Dec 17 19:44 WORK -> /home/mattdm/work
lrwxrwxrwx. 1 mattdm mattdm  8 Dec 17 19:44 www -> /srv/www
$ jd tmp
$ pwd
/home/mattdm/tmp
$ jd WORK
/home/mattdm/work

And, for an extra dose of fancy, make jd list all of your shortcuts when executed without any parameters:

jd()
{
    if [[ -z "$1" ]]; then
      (cd ~/.shortcuts; stat -c '%N' *)
    else
      cd -P ~/.shortcuts/$1
    fi
}

Note: I use compgen -W $( cmd ) instead of compgen -C 'cmd' because the latter never works for me and I don't understand why. That might be a new question of my own. :)