Reading HTML e-mail with Mutt

Glory be! It’s pretty easy to get nicely formatted output of those sneaky HTML e-mail messages (which all the young Internet kids are sending nowadays).

In your ~/.mailcap, if you use w3m (as I do):
text/html; w3m %s -o display_link_number=1; nametemplate=%s.html
text/html; w3m -dump %s -o display_link_number=1; nametemplate=%s.html; copiousoutput

And in your ~/.muttrc:
auto_view text/html

The Debian Administration site tells you how!


Ubuntu batch photo processing

Way-cool batch photo processing on Ubuntu, GNU/Linux, Windows, and Mac with Phatch.

Enabling Apache’s PHP execution in User Directories on Ubuntu Lucid

Ubuntu Lucid ships with PHP disabled for user directories. That’s a sensible security default, but it won’t allow your developers to get their work done. And if you’re working with Drupal, you’ll need all the steps listed here.

First, you’ll need to install Apache:
sudo apt-get install apache2

Then the compiled PHP binary (or “shared object” in Apache lingo):
sudo apt-get install php5

You may need to do sudo /etc/init.d/apache2 restart or sudo service apache2 restart to have it pick up the updated configuration file that loads the PHP5 module. Try visiting your own box at “localhost” to see if you get a nice “welcome” page. You can put an “info.php” file in /var/www to test if PHP is working (the contents of your info.php file are simply <?php phpinfo(); ?>), and visit that in your browser.

Once you’ve gotten PHP running under Apache, edit /etc/apache2/mods-available/php5.conf and comment out the lines as instructed:

<IfModule mod_php5.c>
    <FilesMatch "\.ph(p3?|tml)$">
        SetHandler application/x-httpd-php
    <FilesMatch "\.phps$">
        SetHandler application/x-httpd-php-source
    # To re-enable php in user directories comment the following lines
    # (from <IfModule ...> to </IfModule>.) Do NOT set it to On as it
    # prevents .htaccess files from disabling it.
#    <IfModule mod_userdir.c>
#        <Directory /home/*/public_html>
#            php_admin_value engine Off
#        </Directory>
#    </IfModule>

If you’re developing with Drupal, the following step may also be necessary: In /etc/apache2/mods-available/userdir.conf, you should allow Drupal’s local .htaccess file to override the Apache-wide configuration file, with:

        <Directory /home/*/public_html>
                AllowOverride All
                #AllowOverride FileInfo AuthConfig Limit Indexes
                #Options MultiViews Indexes SymLinksIfOwnerMatch IncludesNoExec

Restart Apache with sudo /etc/init.d/apache2 restart and you might be done!

Ignoring Ubuntu Upstart for System V compatibility

If you’d like to start an Ubuntu service using the System V-compatible runlevels, use “update-rc.d.” For example:

# update-rc.d ssh defaults
update-rc.d: warning: ssh stop runlevel arguments (0 1 6) do not match LSB Default-Stop values (none)
Adding system startup for /etc/init.d/ssh ...
/etc/rc0.d/K20ssh -> ../init.d/ssh
/etc/rc1.d/K20ssh -> ../init.d/ssh
/etc/rc6.d/K20ssh -> ../init.d/ssh
/etc/rc2.d/S20ssh -> ../init.d/ssh
/etc/rc3.d/S20ssh -> ../init.d/ssh
/etc/rc4.d/S20ssh -> ../init.d/ssh
/etc/rc5.d/S20ssh -> ../init.d/ssh

Split a file across multiple CDs or DVDs on Linux

Okay, so you very likely have the ‘split’ utility installed (it’s in the GNU coreutils package, so… very likely). If you want to burn a file to multiple media, but you don’t have kdar installed on your desktop… don’t worry about it. Just open a terminal and do:
$ split --bytes=600MB --numeric-suffixes filename_part_
In my case, I have a 2.8GB file, but I only have 700MB CDs on hand for my burner. So this command will ensure that I get several 600 “megabyte” (1000 bytes * 1000) pieces, named “filename_part_00,” “filename_part_01,” and “filename_part_02,” et cetera.

Remove user list from Ubuntu 9.10 Karmic Koala login screen

Problem: You want to login to your Ubuntu laptop without letting others shoulder surf your full name. You’d like to introduce yourself to them personally instead.

Solution: In a terminal (Applications -> Accessories -> Terminal), enter

sudo -u gdm gconftool-2 --set --type boolean /apps/gdm/simple-greeter/disable_user_list true

Type in your password when requested. You’re done.

sftp chroot jail in Ubuntu

(Update 16 Mar 2011: Since writing this post, I’ve learned of an easier way to create this chroot jail. Newer versions of OpenSSH enable the “ChrootDirectory” configuration directive. I recommend that you take a look at George Ornbo’s tutorial on chrooting sftp users in Intrepid for the details.)

(Updated 08 Feb 2011 to reflect xplicit’s experience on Ubuntu 10.04.)

I wanted to give a buddy access to a website hosted on my box. So I tried scponly, since I only wanted to provide SFTP access to that particular directory, using a chroot jail. The steps are as follows.

  1. Install the scponly package using Ubuntu’s APT package management system.
  2. Use the script provided to set up your first jail and your user’s home directory. For the location of the user’s jail, give the path of the directory you want to share.
  3. Provide a password for the new user.
  4. Ensure that the new user has permissions to read and write all the necessary directories in your Web site.

$ sudo apt-get install scponly
$ gzip -dc /usr/share/doc/scponly/setup_chroot/ > /tmp/
$ cp /usr/share/doc/scponly/setup_chroot/config.h /tmp

The previous step copies the “config.h” file to help things go more smoothly, as Luke found.

$ chmod +x /tmp/
$ cd /tmp
$ sudo ./

Next we need to set the home directory for this scponly user.
please note that the user's home directory MUST NOT be writeable
by the scponly user. this is important so that the scponly user
cannot subvert the .ssh configuration parameters.
For this reason, a writeable subdirectory will be created that
the scponly user can write into.

Note that I removed the /incoming subdirectory created by this script. There was no need for a separate directory for my buddy to upload files. He could have permissions over the whole site tree.

-en Username to install [scponly]
-en home directory you wish to set for this user [/home/bob]
-en name of the writeable subdirectory [incoming]

creating /var/www/sites/bobsite/htdocs/incoming directory for uploading files

Your platform (Linux) does not have a platform specific setup script.
This install script will attempt a best guess.
If you perform customizations, please consider sending me your changes.
Look to the templates in build_extras/arch.
- joe at sublimation dot org

please set the password for bob:
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
if you experience a warning with winscp regarding groups, please install
the provided hacked out fake groups program into your chroot, like so:
cp groups /var/www/sites/bobsite/htdocs/bin/groups

This script added certain directories to the site root (/var/www/sites/bobsite/htdocs). Every other directory needed to be writable by Bob. So let’s add Bob to a special group, and allow that group write access on all the website’s files.

$ sudo adduser bob www-data

We can ignore /bin, /etc, /lib and other directories added to the chroot jail (the website filesystem):

$ sudo find . \! -user root -exec chgrp www-data \{\} \;
$ sudo find . \! -user root -exec chmod g+w \{\} \;

Good to go!