Hashbang (Shebang)

In Unix, Linux or Linux-like systems, scripts can be given execution rights by

chmod +x script_filemane

And run as ordinary applications. These scripts are called executable scripts.

The first line of an executable script is special. It starts with #!- (hashbang or shebang), telling the system where to find the program to run the scripts. For example:

#!/usr/local/opt/python/libexec/bin/python
print('The bright side' + ' of life...')

We can use the Linux env lookup hack to make the scripts more portable (assuming the env utility is always located at /usr/bin/env).

#!/usr/bin/env python
print("The bright side of life...")