如何在ZSH中使PATH更简洁？

Question

I am using ZSH. I was having trouble running the Anaconda package manager commands in my terminal. I found that I could add the bin to my PATH using this code:

export PATH="$HOME/anaconda3/bin:$PATH"

That worked. All of the Anaconda and associated commands work and it left me with this PATH:

/Users/USER/anaconda3/bin:/Library/Frameworks/Python.framework/Versions/3.6/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/opt/X11/bin

But the PATH variable would reset each time I closed the terminal window. After some research, I figured out how modify my .zshrc to make it permanent. I simply pasted this into my .zshrc:

export PATH=/Users/USER/anaconda3/bin:/Library/Frameworks/Python.framework/Versions/3.6/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/opt/X11/bin

All the commands work and are permanent, but aren't I setting myself up for failure down the road? Everything in the PATH, minus the "/Users/USER/anaconda3/bin" were set automatically. What happens when I update Python, for example? How can I include the "USER/anaconda3/bin" portion of my PATH in my .zshrc without being so explicit?

Answer 1

Your PATH concern is not zsh specific. You could organize things differently.

For example, you could decide to add a directory $HOME/bin/ early in your PATH and put inside that $HOME/bin/ symbolic links to the executables (or scripts ) that you want to use. BTW, I recommend to have a short PATH (containing some $HOME/bin/ etc...) since it is more efficient and less messy to understand.

What happens when I update Python, for example?

Let's suppose that Python is installed in your system in /usr/bin/python (and that you use some Linux distribution -or some other Unix- with a good package manager dealing with that;on MacOSX consider homebrew ). When that file /usr/bin/python is updated, any future exec of it (eg by some shell) will use the new version. Read carefully execve(2) .

If ou have several Python-s and the one you want to use is under /Library/Frameworks/Python.framework/Versions/3.6/bin and you upgraded it to some Python 3.7 installed under /Library/Frameworks/Python.framework/Versions/3.7/bin you would need to change your PATH .

If you followed my suggestion, you would (for example) just have a symlink from $HOME/bin/python to /Library/Frameworks/Python.framework/Versions/3.6/bin/python and you would upgrade that symlink when installing Python3.7 using for example:

# remove the old symlink
rm -v $HOME/bin/python
# add the new one
ln -sv /Library/Frameworks/Python.framework/Versions/3.7/bin/python \
   $HOME/bin/python

In all cases, you are responsible of having a good enough PATH (and preferably a short one).