#869 - Detect the shell dialect from the hashbang for shellcheck

autoload/ale/handlers/sh.vim

@@ -0,0 +1,20 @@
+" Author: w0rp <devw0rp@gmail.com>
+
+" Get the shell type for a buffer, based on the hashbang line.
+function! ale#handlers#sh#GetShellType(buffer) abort
+    let l:bang_line = get(getbufline(a:buffer, 1), 0, '')
+
+    " Take the shell executable from the hashbang, if we can.
+    if l:bang_line[:1] is# '#!'
+        " Remove options like -e, etc.
+        let l:command = substitute(l:bang_line, ' --\?[a-zA-Z0-9]\+', '', 'g')
+
+        for l:possible_shell in ['bash', 'tcsh', 'csh', 'zsh', 'sh']
+            if l:command =~# l:possible_shell . '\s*$'
+                return l:possible_shell
+            endif
+        endfor
+    endif
+
+    return ''
+endfunction