Why does emacs sh-mode ignore indent-tabs-mode?

Question

sh-mode won't care if indent-tabs-mode is on, it will still insert spaces instead of tabs! Can this be fixed?

Answer 1

I'm going to guess that tab-width and sh-basic-offset are not aligned.

indent-tabs-mode will only use tabs to indent up to multiples of tab-width, as otherwise it would indent too much.

That said, I find tabs bad for shell script indentation, as copying and pasting code from a script into a shell running in a terminal can be problematic. I would recommend using spaces for shell scripts for this reason.

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Edit: In this instance it was the backspace behaviour which was causing confusion.

C-hkDEL tells me:

DEL (translated from <backspace>) runs the command
backward-delete-char-untabify (found in sh-mode-map), which is an
interactive compiled Lisp function in ‘simple.el’.

It is bound to DEL.

(backward-delete-char-untabify ARG &optional KILLP)

Delete characters backward, changing tabs into spaces.
The exact behavior depends on ‘backward-delete-char-untabify-method’.
Delete ARG chars, and kill (save in kill ring) if KILLP is non-nil.
Interactively, ARG is the prefix arg (default 1)
and KILLP is t if a prefix arg was specified.

Follow the link provided there and set backward-delete-char-untabify-method to nil so that it deletes a single character (which should be a tab) each time.