Add g:suda#nopass to skip password prompt (#53)

* nopass option

* nopass option in README

* nopass: suggested fixes

* suda#nopass variable fix

* nopass: add variable to the docs

* Fix docs

* Apply lexical order

Co-authored-by: Lanius <laniuspne@pm.me>

Author: lambdalisue

README.md

@@ -69,3 +69,7 @@ Make sure that the following shows `1`.
 ```vim
 : echo executable('sudo')
 ```
+
+### Use sudo without a password
+
+When `let g:suda#nopass = 1` is written in your vimrc, suda won't ask you for a password. Use at your own risk.

autoload/suda.vim

@@ -1,5 +1,5 @@
 function! suda#system(cmd, ...) abort
-  let cmd = has('win32')
+  let cmd = has('win32') || g:suda#nopass
         \ ? printf('sudo %s', a:cmd)
         \ : printf('sudo -p '''' -n %s', a:cmd)
   if &verbose
@@ -263,4 +263,5 @@ augroup suda_internal
 augroup END
 
 " Configure
+let g:suda#nopass = get(g:, 'suda#nopass', 0)
 let g:suda#prompt = get(g:, 'suda#prompt', 'Password: ')

doc/suda.txt

@@ -160,6 +160,12 @@ suda#write({expr} [, {options}])
 -----------------------------------------------------------------------------
 VARIABLE					*suda-interface-variable*
 
+*g:suda#nopass*
+	If set, suda will not prompt you for a password before saving a file.
+	It is suppossed to support a setup with passwordless sudo or doas.
+	Use with care.
+	Default: 0
+
 *g:suda#prompt*
 	A prompt string used to ask password.
 	Default: "Password: "