How do I install a script to run anywhere from the command line?

Type echo $PATH in a shell. Those are the directories searched when you type command, so put it in one of those.

Edit: Apparently don’t use /usr/bin, use /usr/local/bin

Acording to FHS, the /usr/local/bin/ is the good place for custom scripts.
I prefer to make them 755 root:root, after copying them there.

Putting the script somewhere in the PATH (like /usr/local/bin) is a good solution, but this forces all the users of your system to use/see your script.

Adding an alias in /etc/profile could be a way to do what you want allowing the users of your system to undo this using the unalias command. The line to be added would be:

alias MyScript=/path/to/file/MyScript

Just create ~/bin and put export PATH=$PATH:$HOME/bin in your bashrc/profile. Don’t mess with the system, it will bite you back, trust me.

Few more things (relevant to the question but not part of the answer):

1. The other way export PATH=$HOME/bin:$PATH is NOT safe, for bash will will look into your ~/bin folder for executables, and if their name matches with other executables in your original $PATH you will be surprised by unexpected/non working command execution.
2. Don’t forget to chmod+x when you save your script in ~/bin.
3. Be aware of what you are putting in your ~/bin folder, if you are just testing something or working on unfinished script, its always better to use ./$SCRIPT_NAME from your CWD to execute the script than putting it under ~/bin.

Walkthrough of making a python script available anywhere:

Make a python script:

cd /home/el/bin
touch stuff.py
chmod +x stuff.py

Find out where your python is:

which python
/usr/bin/python

Put this code in there:

#!/usr/bin/python
print "hi"

Run in it the same directory:

python stuff.py

Go up a directory and it’s not available:

cd ..
stuff.py

-bash: stuff.py: command not found

Not found! It’s as we expect, add the file path of the python file to the $PATH

vi ~/.bashrc

Add the file:

export PATH=$PATH:/home/el/bin

Save it out, re apply the .bashrc, and retry

source ~/.bashrc

Try again:

cd /home/el
stuff.py

Prints:

hi

The trick is that the bash shell knows the language of the file via the shebang.

The quick answer is to symlink your script to any directory included in your system $PATH.

The long answer is described below with a walk through example, (this is what I normally do):

a) Create the script e.g. $HOME/Desktop/myscript.py:

#!/usr/bin/python
print("Hello Pythonista!")

b) Change the permission of the script file to make it executable:

$ chmod +x myscript.py

c) Add a customized directory to the $PATH (see why in the notes below) to use it for the user’s scripts:

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

d) Create a symbolic link to the script as follows:

$ ln -s $HOME/Desktop/myscript.py $HOME/bin/hello

Notice that hello (can be anything) is the name of the command that you will use to invoke your script.

Note:

i) The reason to use $HOME/bin instead of the /usr/local/bin is to separate the local scripts from those of other users (if you wish to) and other installed stuff.

ii) To create a symlink you should use the complete correct path, i.e.

$HOME/bin GOOD ~/bin NO GOOD!

Here is a complete example:

 $ pwd
 ~/Desktop
 $ cat > myscript.py << EOF
 > #!/usr/bin/python
 > print("Hello Pythonista!")
 > EOF
 $ export PATH="$PATH:$HOME/bin"
 $ ln -s $HOME/Desktop/myscript.py $HOME/bin/hello
 $ chmod +x myscript.py
 $ hello
Hello Pythonista!

Just create symbolic link to your script in /usr/local/bin/:

sudo ln -s /path/to/your/script.py /usr/local/bin/script

you can also use setuptools (https://pypi.org/project/setuptools/)

1. your script will be:

def hi():
    print("hi")

(suppose the file name is hello.py)

2. also add __init__.py file next to your script (with nothing in it).

3. add setup.py script, with the content:

#!/usr/bin/env python3

import setuptools

install_requires = [
        'WHATEVER PACKAGES YOU NEED GOES HERE'
        ]

setuptools.setup(
    name="some_utils",
    version="1.1",
    packages=setuptools.find_packages(),
    install_requires=install_requires,
    entry_points={
        'console_scripts': [
            'cool_script = hello:hi',
        ],
    },
    include_package_data=True,
    )

4. you can now run python setup.py develop in this folder
5. then from anywhere, run cool_script and your script will run.

i find a simple alias in my ~/.bash_profile or ~/.zshrc is the easiest:

alias myscript="python path/to/my/script.py"