BASH linter

I use a linter for BASH called ShellCheck, it can be installed on Debian based systmes with:

# apt-get install shellcheck

You can then invoke it simply from the command line to get feedback on your shell script. The messages are colour coded to indicate their severity: green, yellow and red:

$ shellcheck shellcheck-test.sh

In shellcheck-test.sh line 3:
read_user_input() {
^-- SC2120: read_user_input references arguments, but none are ever passed.


In shellcheck-test.sh line 5:
    echo $el
         ^-- SC2086: Double quote to prevent globbing and word splitting.


In shellcheck-test.sh line 6:
    i=1
    ^-- SC2034: i appears unused. Verify it or export it.


In shellcheck-test.sh line 11:
  read_user_input
  ^-- SC2119: Use read_user_input "$@" if function's $1 should mean script's $1.


In shellcheck-test.sh line 15:
main $@
     ^-- SC2068: Double quote array expansions, otherwise they're like $* and break on spaces.

Emacs integration

It's easy getting on the fly linting of the BASH scripts you're working on by installing flycheck:

M-x package-install flycheck

and enable it everwhere:

(setq global-flycheck-mode t)

It will now pick up whatever linting tool you've installed for the current mode, e.g. shellcheck. For a list of all languages and linting tools it supports out of the box, have a look at this list .

flycheck bash