What is difference between dir and dir/ in linux terminal or in dos?

For Example : In any command when we need to refer any directory. Then we use dirname or dirname/

what is the difference between them?

For e.g. cd dirname vs cd dirname/

and cp -R dirname1 dirname2 vs cp -R dirname1 dirname2/ vs c开发者_如何学Gop -R dirname1/ dirname2/

dirname is the directory. dirname\ is a path whose last node is the directory.

In most contexts you can get away with using either, but that's not always the case.

Usually if you're trying to, say, copy a file into a directory, cp file dirname\ to make clear that you're copying it to a new path. Visualise file being appended to the path, to become dirname\file. This is most important when working with symbolic links, as the file system isn't quite as clever at auto-translating dirname to dirname\ as required, when dirname is a symlink.

For linux shell: In general, either one will work. Assuming the two filenames actually are directories, including or omitting the final slash should be optional.

Cases where you might notice a difference:

• if dirname is actually a symbolic link to a directory, using the final / will fail
• a few commands, like rsync, specifically treat filename arguments ending with / differently

At least in a DOS/Windows shell, there usually is no difference. There is one exception I know:

If you use

xcopy somefile C:\somepath

and somepath doesn't exist, xcopy asks if somepath is a file or a directory to be created, which can be avoided using

xcopy somefile C:\somepath\

which will just create somepath and copy somefile in there.

So in that case, somepath\ makes it clearer that it's a path. Anyway, usually you're referring to a path that already exists, so there'll be no difference between the two cases.