Add new user option 'cperl-file-style'

* lisp/progmodes/cperl-mode.el (cperl-file-style): New user option
(bug#17948).
(cperl-mode): Mention it.
(cperl-style-alist): Mention it.

etc/NEWS

@@ -786,6 +786,11 @@ so automatically.
 
 * Changes in Specialized Modes and Packages in Emacs 29.1
 
+---
+*** New user option 'cperl-file-style'.
+The determines the indentation style to be used.  This can also be
+used as a file-local variable.
+
 ---
 *** 'gud-go' is now bound to 'C-c C-v'.
 If given a prefix, it will query the user for an argument to use for

lisp/progmodes/cperl-mode.el

@@ -558,6 +558,19 @@ This way enabling/disabling of menu items is more correct."
   :type 'boolean
   :group 'cperl-speed)
 
+(defcustom cperl-file-style nil
+  "Indentation style to use in cperl-mode."
+  :type '(choice (const "CPerl")
+                 (const "PBP")
+                 (const "PerlStyle")
+                 (const "GNU")
+                 (const "C++")
+                 (const "K&R")
+                 (const "BSD")
+                 (const "Whitesmith"))
+  :version "29.1")
+;;;###autoload(put 'cperl-file-style 'safe-local-variable 'stringp)
+
 (defcustom cperl-ps-print-face-properties
   '((font-lock-keyword-face		nil nil		bold shadow)
     (font-lock-variable-name-face	nil nil		bold)
@@ -1660,9 +1673,11 @@ Settings for classic indent-styles: K&R BSD=C++ GNU PBP PerlStyle=Whitesmith
   `cperl-continued-statement-offset'  5   4       2   4   4
 
 CPerl knows several indentation styles, and may bulk set the
-corresponding variables.  Use \\[cperl-set-style] to do this.  Use
-\\[cperl-set-style-back] to restore the memorized preexisting values
-\(both available from menu).  See examples in `cperl-style-examples'.
+corresponding variables.  Use \\[cperl-set-style] to do this or
+set the `cperl-file-style' user option.  Use
+\\[cperl-set-style-back] to restore the memorized preexisting
+values \(both available from menu).  See examples in
+`cperl-style-examples'.
 
 Part of the indentation style is how different parts of if/elsif/else
 statements are broken into lines; in CPerl, this is reflected on how
@@ -1795,6 +1810,8 @@ or as help on variables `cperl-tips', `cperl-problems',
   (when (and cperl-pod-here-scan
              (not cperl-syntaxify-by-font-lock))
     (cperl-find-pods-heres))
+  (when cperl-file-style
+    (cperl-set-style cperl-file-style))
   ;; Setup Flymake
   (add-hook 'flymake-diagnostic-functions #'perl-flymake nil t))
 
@@ -6313,7 +6330,7 @@ else
      )
     ("Current"))
   "List of variables to set to get a particular indentation style.
-Should be used via `cperl-set-style' or via Perl menu.
+Should be used via `cperl-set-style', `cperl-file-style' or via Perl menu.
 
 See examples in `cperl-style-examples'.")