Bash: Getting all parts of a filespec

[wazoo]

I am very new to bash and linux, and having a bear of a time extracting strings from filespecs. Most solutions give me the pwd, or the basename, but I am really ALSO need to get the directory path BEFORE the file or folder.

Can someone please give me a simple bash routine or set of functions that will (complete with the correct way to call the function, and some sample of output expected):

Take a partial OR fully qualified filespec passed to my script:
eg. folderName OR fileName (could be either)
eg /home/bin/folderName OR /home/bin/fileName.html

and give me these key parts of the spec

1) basename= (eg "folderName/" OR "fileName")
2) file extension = (eg html, if applicable)
3) preceding filePath= /home/bin/sub1/ (even if script called from current dir)


Judging from the dozens of partial solutions aroud the web, I think this would help many. THanks in advance!

[wazoo]

No sooner did I post, than I came across this. I think it's the answer

bash String Manipulations Issue 18

EXCERPT FROM ARTICLE
Given:
foo=/tmp/my.dir/filename.tar.gz

We can use these expressions:

path = ${foo%/*}
To get: /tmp/my.dir (like dirname)
file = ${foo##*/}
To get: filename.tar.gz (like basename)
base = ${file%%.*}
To get: filename
ext = ${file#*.}
To get: tar.gz