8

I have an alias for a command (I'm setting up a Python development environment)

alias python=~/virtualenv/bin/python

so that I can run ~/virtualenv/bin/python by just typing python. Now in my project there is a shell script that goes, for example:

#!/bin/sh
python run-project.py

Can I make the script use my aliased python instead of the python it finds in $PATH, without making changes to the script?

phunehehe
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3 Answers3

7

Yes.

If you put your aliases in ~/.aliases, then you can do

export BASH_ENV="~/.aliases"
somescript

This assumes your script starts with #!/bin/bash, because #!/bin/sh is a little less predictable.

Here's what I'd suggest:

  1. Create ~/.bashenv
  2. Move all the settings that you want to work in scripts from ~/.bashrc into ~/.bashenv
  3. Add this at the top of your ~/.bashrc:
    [ -f ~/.bashenv ] && source ~/.bashenv
  4. Put BASH_ENV=~/.bashenv in /etc/environment
  5. Make your scripts start with #!/bin/bash if they don't already

Or, if you're using zsh, just move your aliases into ~/.zshenv. zsh looks in that file automatically.

But maybe it's easier to just put ~/virtualenv/bin near the front of your PATH, then change your Python scripts to have #!/usr/bin/env python as the first line.

Mikel
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  • Don't you mean `~/.bashenv` in step 4? – cjm Mar 02 '11 at 02:47
  • So I'll have to change the script anyway, from `#!/bin/sh` to `#!/bin/bash`? Can I just do `bash my-script`? – phunehehe Mar 02 '11 at 02:48
  • phunehehe: Yes, I think `bash my-script` will work if you still do steps 1-4. – Mikel Mar 02 '11 at 02:50
  • I don't recommend using aliases in scripts. It won't work if someone else runs your script, or if you run the script under `sudo` or other privilege elevation method. And it doesn't allow you to change the `virtualenv` per execution, which would be the main point of not having `~/virtualenv/bin` in your `PATH` permanently. Adding the directory in front of the `PATH` when needed is the best method. – Gilles 'SO- stop being evil' Mar 02 '11 at 08:02
4

Supposing that your alias file is "~/.bash_aliases", put this in your script:

#!/bin/bash
shopt -s expand_aliases
source ~/.bash_aliases
python run-project.py

(via)

Community
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tshepang
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0

Alternatively, you can always source your script to forcely use the aliases. For example, let's assume you have an alias of rm in your ~/.bashrc:

alias rm='moveToTrash'

while moveToTrash is a program in your /usr/bin. Now you have a script named test.bash like this:

#!/bin/bash

which rm

When test.bash is execute directly, you can see the output /bin/rm, while source test.bash will get the output 

alias rm='moveToTrash'
    /usr/bin/moveToTrash
Mark Z.
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