Command to establish whether Directory or Link exists?

Question

I need to run a command that checks whether a Directory or Link exists at a specific location, and if it is a directory to rename it.
Any ideas?

Answer 1

While Cole Tierney's style is valid (and I use it myself), sometimes an if/then/else structure is easier to understand
# doing something if a directory or symlink
if [[ -d aname || -h aname ]]; then
dosomething
fi
# renaming a directory
if [[ -d aname ]]; then
mv aname newname
fi
If you do not really care if it is a symlink, but only that it is a directory or a symlink that points to a directory then:
if [[ -d aname ]]; then
dosomething because aname leads to a directory
fi
While not always easy to read, the "man bash" man page will give you the -d and -h test options along with a long list of other tests you can do on files.
There are also several books on the bash shell, which can be reviewed over a cup of coffee in your local bookstore cafe.