From 6b072b27ee12c944142e310c984df028118713da Mon Sep 17 00:00:00 2001
From: Phil Hagelberg <phil@evri.com>
Date: Fri, 21 Jan 2011 21:20:57 -0500
Subject: [PATCH] Add pcomplete support for hosts defined in .ssh/config.

* lisp/pcmpl-unix.el (pcmpl-ssh-config-file): New option.
(pcmpl-ssh-known-hosts): Rename from pcmpl-ssh-hosts.
(pcmpl-ssh-config-hosts): New function.
(pcmpl-ssh-hosts): Use pcmpl-ssh-config-hosts in addition to
pcmpl-ssh-known-hosts.
---
 lisp/ChangeLog     |  8 ++++++++
 lisp/pcmpl-unix.el | 40 +++++++++++++++++++++++++++++++++++-----
 2 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index cf51ddc109a..22fee77f584 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,11 @@
+2011-01-22  Phil Hagelberg  <phil@evri.com>
+
+	* pcmpl-unix.el (pcmpl-ssh-config-file): New option.
+	(pcmpl-ssh-known-hosts): Rename from pcmpl-ssh-hosts.
+	(pcmpl-ssh-config-hosts): New function.
+	(pcmpl-ssh-hosts): Use pcmpl-ssh-config-hosts in addition to
+	pcmpl-ssh-known-hosts.
+
 2011-01-21  Jay Belanger  <jay.p.belanger@gmail.com>
 
 	* calc/calc-undo.el (calc-undo): Autoload it.
diff --git a/lisp/pcmpl-unix.el b/lisp/pcmpl-unix.el
index 9b3857842fe..bbeb615d5b7 100644
--- a/lisp/pcmpl-unix.el
+++ b/lisp/pcmpl-unix.el
@@ -40,14 +40,23 @@
 
 (defcustom pcmpl-ssh-known-hosts-file "~/.ssh/known_hosts"
   "If non-nil, a string naming your SSH \"known_hosts\" file.
-This allows completion of SSH host names.  Note that newer
-versions of ssh hash the hosts by default to prevent
-Island-hopping SSH attacks.  This can be disabled, at some risk,
-with the SSH option \"HashKnownHosts no\"."
+This allows one method of completion of SSH host names, the other
+being via `pcmpl-ssh-config-file'.  Note that newer versions of
+ssh hash the hosts by default, to prevent Island-hopping SSH
+attacks.  This can be disabled, at some risk, with the SSH option
+\"HashKnownHosts no\"."
   :type '(choice file (const nil))
   :group 'pcmpl-unix
   :version "23.1")
 
+(defcustom pcmpl-ssh-config-file "~/.ssh/config"
+  "If non-nil, a string naming your SSH \"config\" file.
+This allows one method of completion of SSH host names, the other
+being via `pcmpl-ssh-known-hosts-file'."
+  :type '(choice file (const nil))
+  :group 'pcmpl-unix
+  :version "24.1")
+
 ;; Functions:
 
 ;;;###autoload
@@ -138,7 +147,7 @@ documentation), this function returns nil."
 ;; ssh support by Phil Hagelberg.
 ;; http://www.emacswiki.org/cgi-bin/wiki/pcmpl-ssh.el
 
-(defun pcmpl-ssh-hosts ()
+(defun pcmpl-ssh-known-hosts ()
   "Return a list of hosts found in `pcmpl-ssh-known-hosts-file'."
   (when (and pcmpl-ssh-known-hosts-file
              (file-readable-p pcmpl-ssh-known-hosts-file))
@@ -153,6 +162,27 @@ documentation), this function returns nil."
             (add-to-list 'ssh-hosts-list (match-string 1))))
         ssh-hosts-list))))
 
+(defun pcmpl-ssh-config-hosts ()
+  "Return a list of hosts found in `pcmpl-ssh-config-file'."
+  (when (and pcmpl-ssh-config-file
+             (file-readable-p pcmpl-ssh-config-file))
+    (with-temp-buffer
+      (insert-file-contents-literally pcmpl-ssh-config-file)
+      (let (ssh-hosts-list
+            (case-fold-search t))
+        (while (re-search-forward "^ *host\\(name\\)? +\\([-.[:alnum:]]+\\)"
+                                  nil t)
+          (add-to-list 'ssh-hosts-list (match-string 2)))
+        ssh-hosts-list))))
+
+(defun pcmpl-ssh-hosts ()
+  "Return a list of known SSH hosts.
+Uses both `pcmpl-ssh-config-file' and `pcmpl-ssh-known-hosts-file'."
+  (let ((hosts (pcmpl-ssh-known-hosts)))
+    (dolist (h (pcmpl-ssh-config-hosts))
+      (add-to-list 'hosts h))
+    hosts))
+
 ;;;###autoload
 (defun pcomplete/ssh ()
   "Completion rules for the `ssh' command."
-- 
2.39.2