Dired mode and too many buffers.

Emacs has a very nice file browser/directory editor builtin called Dired. It's convenient when you're searching for files or or just need a general directory browser. You open it with:

C-x d

Supply to the directory that you want, and the directory listing appears in a buffer which you can navigate like any Emacs buffer. You can open files and directories by moving the cursor sand selecting them, as well as delete, rename, move and apply other opperations to the files and directories. All in all, it's pretty slick.

Dired's one major inconvenience for me is that every time I open something, it opens in a separate buffer. This includes new directories. So, if I use it to browse directories I end up with a large backlog of buffers that I have to delete and it gets very annoying.

Fortunatly, this being Emacs, things are eay to fix. A Google search found me this code:

(defun dired-follow-file ()
 "In dired, visit the file or directory on this line.
If a directory is on the current line, replace the current
dired buffer with one containing the contents of the directory.
Otherwise, invoke `dired-find-file' on the file."
 (interactive)
 (let ((filename (dired-get-filename)))
   ;; if the file is a directory, replace the buffer with the
   ;;  directory's contents
   (if (file-directory-p filename)
       (find-alternate-file filename)
     ;; otherwise simply perform a normal `dired-find-file'
     (dired-find-file))))

(add-hook
'dired-mode-hook
(lambda ()
  (local-set-key "\C-m" 'dired-follow-file)
  (local-set-key "e" 'dired-follow-file)
  (local-set-key "f" 'dired-follow-file)))

Which causes Dired to do exactly what I want, with one caveat: for some reason it bombs on . and .. directories. A little bit probing showed that it was dired-get-filename that was was failing for some reasons on these entries. I couldn't find either the definition or a description of dired-get-filename, but did find usage examples through a simple web search and these examples showed the usage:

(dired-get-filename nil t)

Instead of:

(dired-get-filename)

Which seemed to be worth a shor and, in fact, solved the problem.

I also added:

(defun dired-follow-up ()
  "In dired, visit the directory up in the 
hierarchy from this one"
  (interactive)
  (find-alternate-file ".."))

So that ^ would also behave as I wanted. The final code in my .emacs is as follows:

;; dired stuff

(defun dired-follow-file ()
  "In dired, visit the file or directory on this line.
If a directory is on the current line, replace the current
dired buffer with one containing the contents of the directory.
Otherwise, invoke `dired-find-file' on the file."
  (interactive)
  (let ((filename (dired-get-filename nil t)))
    ;; if the file is a directory, replace the buffer with the
    ;;  directory's contents
    (if (file-directory-p filename)
 (find-alternate-file filename)
      ;; otherwise simply perform a normal `dired-find-file'
      (dired-find-file))))

(defun dired-follow-up ()
  "In dired, visit the directory up in the 
hierarchy from this one"
  (interactive)
  (find-alternate-file ".."))

(add-hook
 'dired-mode-hook
 (lambda ()
   (local-set-key "\C-m" 'dired-follow-file)
   (local-set-key "e" 'dired-follow-file)
   (local-set-key "f" 'dired-follow-file)
   (local-set-key "^" 'dired-follow-up)))

PhpPgAdmin for Gentoo

I just spent an afternoon getting PhpPgAdmin working on my Gentoo server. There were a couple of pitfalls that tripped me up so I thought I'd relate the process.

To get PhpPgAdmin working you need three things: Postgres (of course), Php, and a webserver. Postgres, I already had installed and working following this tutorial. Rather than emerging the default Postgres package which is version 8.2, I emerged the latest package 8.3. So:

emerge -av virtual/postgresql-base #emerge the database
passwd postgres #set a password for the db user
New UNIX password:
Retype new UNIX password:
passwd: password updated successfully
emerge --config =postgresql-8.3.5 #(now 8.3.7), finish the install
/etc/init.d/postgresql start #start the database
rc-update add postgresql default #and, of course, add to the default runlevel

You can then configure the users to your hearts content using the createuser and dropuser commands. In addition, make sure to edit pg_hba.conf to allow all the connections you need. Make sure local, unix socket, connections are available. Is should be available under /var/lib/postgresql/8.3/data/pg_hba.conf. Also, make sure any users that will need to locally access the database are in the Postgres group.

usermod -aG postgres username

Keep in mind that whatever user your webserver runs as will also need to be added.

Which, brings us to the next step: the webserver. For reasons unreleated to PhpPgAdmin I already had an install of Lighttpd, and I wanted to use it rather than the standard Apache2. After fiddling for a while I reallized that I would have to reemerge it with the fastcgi and php flags enables (they are not enabled by default.) So:

echo "www-servers/lighttpd fastcgi php" >> /etc/portage/package.use #enable flags
emerge -av lighttpd #emerge lighttpd
/etc/init.d/lighttpd start #start the server
rc-update add lighttpd default #make sure it starts on restart

Php is a straightforward install:

echo "dev-lang/php cgi" >> /etc/portage/package.use
emerge -av php

You may wany to set cgi.fix_pathinfo to 1 in php.info:

vim /etc/php/cgi-php/php.ini

Before you install PhpPgAdmin, change vhost_server to whatever webserver you installed. It defaults to Apache, so if you used Lighttpd, change it to that. This file is /etc/vhosts/webapp-config/. And we can install PhpPgAdmin:

emerge -av phppgadmin

That should be it. You can access it through http://your.domain.com/phppgadmin using whatever login you made for Postgres.