What's the standard for indentation in shell scripts? 2 or 4 spaces or 1 tab?
I've never encountered shell specified style guide but for bash programming this is the most popular one:
The indentation of program constructions has to agree with the logic nesting depth. The indentation of one step usually is in line with the tabulator steps of the editor selected. In most cases 2, 4 or 8 are chosen.
The Google Style Guide says 2 spaces
Agree with others that it is an arbitrary choice.
Its source code is hosted at: https://github.com/google/styleguide