如何确定 conda 是否已经在 bash 脚本中的机器上可用？

Question

I want to create a bash script to install a new virtual environment "ABC" in conda. But before I go ahead and run a command to create this env, I want to check if conda is already installed on the machine. If not installed, I want to install miniconda and then create the env "ABC". If conda is already installed then I would just go ahead and create the environment. (All this should happen within the same script) I just want to know if it is possible to check the existence of conda within a bash script and then proceed with the rest of the installations?

'''

#!/bin/bash
<code_to_check_existence_of_conda_env_here ?>
//If it does not exist, I will run the below code
mkdir -p miniconda3
wget https://repo.anaconda.com/miniconda/Miniconda3-latest-Linux-x86_64.sh -O 
miniconda3/miniconda.sh
bash miniconda3/miniconda.sh -b -u -p ~/miniconda3
conda env update -f my_env.yml

'''

Answer 1

The main issue here is that Conda has multiple components. Which components are loaded depends on the how Conda is installed and what user the BASH script is executing under. I'll try describing the components and hopefully you can decide what is suitable to verify.

Conda Components

1: Conda Package

The first is a Python package conda , which is installed in the Anaconda/Miniconda/Miniforge base environment. If the base environment is activated , one could test

python -m conda

which will give something like

/path/to/python: No module named conda

if it isn't there. Otherwise, it outputs the conda entrypoint's documentation.

2: Conda Entrypoint

The entrypoint conda , which acts as a CLI, is located under the condabin directory of the Anaconda/Miniconda/Miniforge installation. When a user runs conda init , a managed section is added to their shell initialization file ( .bashrc for Linux BASH), that includes code to add the condabin to PATH. This is most likely what OP wants to identify, however, running with the shebang /bin/bash will not load the .bashrc file. Instead, one should probably be using

#!/bin/bash -l

or

#!/usr/bin/env bash -l

Then the entrypoint can be located with

which conda

3: Conda Activate

Finally, Conda also includes some shell-only functions, which are defined in the aforementioned shell initialization code. This sets up a middleman shell function, also called conda (essentially an alias), which can be viewed with

type conda

This function serves to determine whether the conda (de)?activate commands are being requested, which are pure shell functions, or something that needs to be forwarded to the entrypoint.

Recommendation

Were I designing this, I would write an interactive script that checks for #2 ( which conda ) and if that comes up blank then prompt the user to either provide the PATH to the Conda entrypoint (maybe they installed it in a weird place or didn't run conda init ) or install Miniforge. ¹

I also would not use the base environment to install stuff - that is a bad idea for an end-user, let alone a third-party - and instead create a new environment. I would prompt the user with a specific default environment name, but also provide an option for them to customize.

---

[1] Yes, Miniforge, not Miniconda. Commercial use of the Anaconda defaults channels now requires a paid license, so better to use the free Miniforge.

Answer 2

I'm not really good at bash scripting but I would execute a command:

pip3 freeze | grep conda

and based on the output (if exit status was an error or not) install it or directly create the environment.

Answer 3

在您的机器上运行命令conda list ，安装和未安装时的输出会有所不同，然后在输出上运行 if 语句。

Answer 4

In bash, if we want to check if a software is installed or not, the following check is used.

if dpkg -l $SOFTWARE; then
<Do stuff>

Answer 5

Type conda activate or conda activate env_name

The first command will activate the base environment if it is already installed. The second command will do activate the user created environment if it is installed.

Answer 6

ensureconda

This sounds like the intended problem that the experimental tool ensureconda was designed to solve. This, however, requires a Python installation with pip:

pip install ensureconda

Here are the command options:

$ ensureconda --help
Usage: ensureconda [OPTIONS]

  Ensures that a conda/mamba is installed.

Options:
  --mamba / --no-mamba            search for mamba
  --micromamba / --no-micromamba  search for micromamba, install if not
                                  present
  --conda / --no-conda            search for conda
  --conda-exe / --no-conda-exe    search for conda.exe / conda-standalone,
                                  install if not present
  --no-install                    don't install conda/mamba if no version can
                                  be discovered
  --min-conda-version VERSIONNUMBER
                                  minimum version of conda to accept (defaults
                                  to 4.8.2)
  --min-mamba-version VERSIONNUMBER
                                  minimum version of mamba/micromamba to
                                  accept (defaults to 0.7.3)
  --help                          Show this message and exit.