What is the difference between /bin and ~/bin?

Question

I am trying to understand exporting paths in Bash, and someone had told me that /bin is not the same as ~/bin. What is the difference between the two?

Solution 1

/bin always refers to the "bin" off of the root directory "/"
In Bash, ~ refers to the users home directory.
thus ~/bin refers to bin off of the user's home directory.

If the user's home is /users/cazs, then ~/bin will be /users/cazs/bin

~ seems to work in the sh shell and its myriad of derivations, including bash, which is what you asked about.

Solution 2

~/bin refers to the bin directory in the current user's home directory. It is equivalent to $HOME/bin. If the current user's home directory is /home/jack, then ~/bin refers to /home/jack/bin.

/bin is an absolute path, its meaning is unambiguous.

Comments

[jasonwryan]

One is a user directory, the other a system one...

[Hack Saw]

Also look at man bash, then search for TILDE EXPANSION.

[Hack Saw]

It's important to note that this is a shell feature, and not always available.

[Hack Saw]

Also, ~bob/bin would refer to something like /users/bob/bin.

[MikeP]

@HackSaw, which shell doesn't support ~?

[Hack Saw]

Most shells that I have used support it. Python doesn't, out of the box. You have to import os.path, and perform an explicit expansion. In general programming languages don't support it, save in libraries.

[MikeP]

@HackSaw, thanks. I was interpreting that some shells don't support it. It is good to note that it is a feature of command line interface (shell), like sh, bash, zsh, csh, tcsh, etc.