Why does ""Here strings" in bash changes the syntax color of whatever follows it?

Question

I am writing a bash script which uses here strings (<<<), please see example below. The script works fine and gives expected output, but the problem is that the (vim) editor syntax color is all messed up after the line where here string was used. Any clues why and also how I can fix it ?

As text:

# get all running screens
scrcmd=$(ps auxw|grep -i screen|grep -v grep|awk '{print $15}')
allscr=()
while read -r line; do
        allscr+=("$line")
done <<< $scrcmd

echo "got screens, now do something else"

Answer 1

The bash (really sh) highlight mode in Vim is multipurpose; it tries to cover POSIX sh, bash, and ksh. You have to tell it you specifically want bash.

:let b:is_bash=1
:set ft=sh

It should highlight properly after that.

If you only ever care about bash, you could just make this your default in .vimrc:

let g:is_bash=1

---

EDIT: As pointed out by Charles Duffy in comments, if you use a #! line, e.g.

#!/bin/bash

#!/usr/bin/env bash

Then vim should do the right thing on its own. That is probably easier, unless you have some reason you prefer not use #! lines.

(Even though that's likely easier, I am leaving my answer here because in this case you do not have a #! line, and that is not uncommon, especially in library code or files expected to be sourced, not executed.)