The problem with vacation auto responders like ‘vacation’ for sendmail is that spammers often fake the From: address. Auto responding to these addresses can get your mail server blacklisted. To avoid this you can setup your autoresponder with procmail and, if you are running a spam filter on your machine, you can tell procmail to auto respond only if the X Spam Status header is ‘No.’ To accomplish this copy the following into ~/.procmailrc in the home directory of the user you want auto responses for. Make sure to make any neccessary changes to MAILDIR, SENDMAIL and the three instances of ‘you@yourdomain.com’:

———————————————

VERBOSE=off
LOGFILE=$HOME/procmail.log
MAILDIR=$HOME/mail
SENDMAIL=/usr/sbin/sendmail
#########################################
# Auto-responder for vacations. Please
# insert text in $MAILDIR/message.txt
#########################################
:0 ic
*!^FROM_DAEMON
*!^X-Loop: you@yourdomain.com
* ^X-Spam-Status: No
|(formail -r -A “Precedence: Auto” \
- -I”From: Testy <you@yourdomain.com>” \
- -I”Subject: Automated acknowledgement” \
- -A “X-Loop: you@yourdomain.com”; \
cat message.txt )| $SENDMAIL -t

———————————————

Now put your auto response message in ~/mail/message.txt . Don’t forget to turn off the autoresponder when you return:

mv ~/.procmailrc ~/procmailrc_backup

There is a bug with numerous NVidia graphics chips that causes the mouse pointer to be invisible in GNOME and GDM (possibly also KDE, I haven’t tried it). I discovered this bug on a fresh install of CentOS 5 but its possible that the issue also applies to CentOS 4 as well as Fedora releases. The fix is relatively easy and solved the problem for me on an nForce motherboard with a built-in GeForce 6100 video card. Edit your xorg.conf file and add the line Option "HWCursor" "off" to your videocard device section so that it looks something like this:

The ever-popular, ever-slick Clearlooks GNOME theme is just minutes away for you CentOS users. Its available via the kbs-CentOS-Extras repo. Download this file and pop it into /etc/yum.repos.d/. Then do

yum install gnome-theme-clearlooks gnome-theme-clearlooks-bigpack

If you’d rather not enable the kbs-CentOS-Extras repo system-wide you can download the packages and install them manually. Get them here and here.

You can also install some other GNOME themes with

yum install gnome-themes-extras

or get the package here.

Now you can install other Clearlooks-based themes like Gilouche as well.

The IEs4Linux project makes installing and running Internet Explorer on Linux a cinch. Just follow these simple instructions. Their script will download and install IE6 and, optionally, IE5 and IE5.5 as well. Everything is automated and extremely easy. You can also install Internet Explorer 7 by following these instructions. I was able to get all four versions of IE running on both my CentOS and Fedora machines in no time. There are non distro-specific instructions as well as instructions for the Ubuntu/Xubuntu/Kubuntu, Fedora, Gentoo and Debian distributions. Basically, if you’re running Linux with Wine and cabextract installed you’re good to go. Many thanks to the IEs4Linux project for making this so easy for us. We should all seriously consider donating to the project.

UPDATED: Mar-21-2007

Due to the popularity of this post I’ve decided to include instructions for all three of the most popular methods for installing Firefox 2 on Fedora Core 6. Read through the three options to decide which works best for you.

Option 1: Via yum with the ‘development’ repo

This command will allow you to upgrade to Firefox 2 via the Fedora Development repo. This is the most commonly recommended option.

Instructions (as root):

# yum --enablerepo=development update firefox

Pros: Uses “official” Fedora packages

Cons: Doesn’t include the (optional) bonuses of option 2

Option 2: Via yum with the ‘remi’ repo

Remi Collet, an “official” Fedora developer, has made available a repo of packages that provides Firefox 2. The repo updates Firefox and those packages that depend on it and also contains a few bonuses such as an updated XChat package (version 2.8).

Instructions (as root):

# rpm -Uvh http://remi.collet.free.fr/rpms/fc6.i386/remi-release-1-2.fc6.remi.noarch.rpm

Now make sure that in your /etc/yum.repos.d/remi.repo file you’ve got enabled=1 and then:

# yum update

Pros: All required packages as well as some extra goodies; new versions of Firefox are automatically installed with yum update

Cons: Not “official” Fedora packages–bugs should not be submitted to the Fedora project

Option 3: Via firefox-2.*.tar.gz from Mozilla.com

I always recommend using RPM packages on Fedora, if possible. However, if you’d like to install Firefox 2 using firefox-2.*.tar.gz from Mozilla.com use this option. One benefit of this option is that Firefox 1.5 remains on your machine so have a choice as to which version to run.

Instructions (as root):

Download firefox-*.tar.gz from Mozilla.com.

# mv firefox-2.*.tar.gz /usr/local/
# cd /usr/local
# tar xvfz firefox-2.*.tar.gz
# mv /usr/bin/firefox /usr/bin/firefox15
# ln -s /usr/local/firefox/firefox /usr/bin/firefox

Firefox 2 will now be your default browser. To run version 1.5 use the command firefox15. I don’t recommend running both versions concurrently because they will be using the same profile which might cause problems.

Pros: Firefox 2 co-exists with version 1.5

Cons: Installation isn’t as straightforward; must be repeated for future releases of Firefox 2

I don’t find myself interested in Windows very often, or any proprietary operating system for that matter, but I ran into this problem on one of the computers in our office and thought I would share the solution. If you come across the problem of spoolsv.exe using 99% CPU usage, never fear. There is a solution. And its a rather easy one. Click here for the fix. Thanks to Tim for his journal entry pointing this out.

I recently added a hard drive to one of my Linux systems and while searching for the best way to copy my old /home filesystem to the new drive I came upon this command:

/sbin/dump 0f - /home | ( cd /new ; /sbin/restore rf - )

Here my new hard drive is mounted on /new and I’m copying the entire filesystem from /home to /new. On my system (CentOS 4) the dump and restore commands are in /sbin/ but other distros may not be consistent so you’ll want to make changes to the command as needed.

UPDATED Dec-19-2006:

NOTE: These instruction are for CentOS 4.

The apt-get method of installing sshfs that I had posted here previously did not work for me. I got this error when trying to mount an ssh drive:

shfsmount: shfs filesystem not supported by the kernel

So, I set out to find a different method of installing sshfs (and fuse, which it requires). One, preferably, that would actually work. Well, I found one. Its not the most elegant solution but its effective.

First, download a copy of the fuse source rpm:

wget http://www.devhen.net/centos/fuse-2.6.0-1.src.rpm

Next, install the source rpm and then build the proper fuse rpm’s from the .spec file:

rpm -ivh fuse-2.6.0-1.src.rpm
rpmbuild -bb /usr/src/redhat/SPECS/fuse.spec

Next, install the rpms that you have built:

cd /usr/src/redhat/RPMS/i386 (replace ‘i386′ with your arch, if necessary)
rpm -Uvh fuse-2.6.0-1.i386.rpm fuse-kernel-2.6.0-1.i386.rpm fuse-libs-2.6.0-1.i386.rpm fuse-devel-2.6.0-1.i386.rpm

Now you can install the sshfs-fuse rpm:

wget http://www.devhen.net/centos/sshfs-fuse-1.6-2.i386.rpm
rpm -ivh sshfs-fuse-1.6-2.i386.rpm

** You can try building the sshfs-fuse rpm from its source package if your not on i386**

Now comes the ugly part… For some reason the system can’t find the fuse module after installing these packages. So, head over to the fuse project homepage and download fuse-2.6.0.tar.gz. Unpack it and then

./configure
make
make install

and you should be in business. As I said, this is not an elegant solution because you are installing fuse from the tar.gz file on top of the fuse rpms. However, it works for me and that’s all that matters right now because I really needed to mount some ssh drives on my workstation.

Mount an ssh drive like so:

sshfs user@remotesystem:/path/you/want/to/mount/ /mnt/mount-point/ -o allow_other

Don’t forget the trailing /’s on both the source folder and the mount point. -o allow_other will give all users access to the mounted drive. Type sshfs -h for a list of all of sshfs’ options.

The latest stable release of Ubuntu Linux comes with Firefox version 1.0.8 installed. Unfortunately this version is slower than 1.5+ and some of the extensions I use only support 1.5+ so, naturally, I needed to upgrade. I found a page on the Ubuntu Wiki called FirefoxNewVersion that shows you how to install a second copy of Firefox, downloaded from the Mozilla web site, alongside Ubuntu’s default Firefox package. Instructions are included on how to change the /usr/bin/firefox script to use the newly installed version instead of the default. This looked like more work than I wanted for a Firefox upgrade–I wanted to stick with .deb packages and didn’t like the idea of having two versions of Firefox installed. So, I discovered a way upgrade my Firefox package using Debain backports. Read on for more.

(Some text taken from the Debian backports instructions)

Add this line

deb http://www.backports.org/debian/ sarge-backports main

to your

/etc/apt/sources.list

and these lines

Package: *
Pin: release a=sarge-backports
Pin-Priority: 200

to your

/etc/apt/preferences

(You may need to create this file if it doesn’t exist)

This will _deactivate_ all packages from backports.org. Now you need to activate the particular packages you want to upgrade from backports.org (e.g. firefox). Upgrading ALL of your packages from backports.org is certain to cause problems. So, we need to add the following text

Package: firefox
Pin: release a=sarge-backports
Pin-Priority: 999

to

/etc/apt/preferences

for each package that we want to allow upgrading via backports.org. We need to do this for firefox and its dependant packages. These include firefox, firefox-gnome-support, language-support-en and mozilla-firefox-locale-en-gb.

Your /etc/apt/preferences file should look something like mine:

Package: *
Pin: release a=sarge-backports
Pin-Priority: 200

Package: firefox
Pin: release a=sarge-backports
Pin-Priority: 999

Package: firefox-gnome-support
Pin: release a=sarge-backports
Pin-Priority: 999

Package: language-support-en
Pin: release a=sarge-backports
Pin-Priority: 999

Package: mozilla-firefox-locale-en-gb
Pin: release a=sarge-backports
Pin-Priority: 999

Now simply run

apt-get update

and

apt-get upgrade firefox

as usual, or launch ’synaptic’, click ‘refresh’ to reload information from your repositories, find your firefox package, mark it to be upgraded and hit apply.

These notes are designed to help a Linux geek setup SMTP auth on a Linux + sendmail server. Without proper SMTP auth settings your server is liable to be used by spammers and spam bots to send out copious amounts of unwanted mail. This can get your server’s IP blacklisted and can really eat up your resources. Needless to say, we need to avoid this. Start by editing your sendmail.mc file (found in /etc/mail). I use the following commands, try replacing the corresponding lines in your mc file with these ones: (Note that lines beginning with ‘dnl’ are essentially considered comments and are ignored)

define(`confAUTH_OPTIONS’, `A’)
dnl
dnl Accept PLAIN and LOGIN authentications.dnl
TRUST_AUTH_MECH(`LOGIN PLAIN’)dnl
define(`confAUTH_MECHANISMS’, `LOGIN PLAIN’)dnl

Now you need to rebuild your sendmail.cf file from the .mc file you’ve just edited:

make sendmail.cf -C /etc/mail

Next we need to make sure saslauthd is running and configured correctly. Edit your saslauthd configuration file (/etc/sysconfig/saslauthd) and replace shadow with pam for the MECH variable like so:

# Mechanism to use when checking passwords. Run “saslauthd -v” to get a list
# of which mechanism your installation was compiled to use.
MECH=pam

Restart sendmail and saslauthd

/etc/rc.d/init.d/sendmail restart
/etc/rc.d/init.d/saslauthd restart

and don’t forget to configure your email clients to use authentication when sending outgoing mail.

For more information and some tips on installing a certificate for secure SMTP connections, try this article:

http://www.madboa.com/geek/sendmail-auth/

Read on for a full copy of my sendmail.mc file.

divert(-1)dnl
dnl #
dnl # This is the sendmail macro config file for m4. If you make changes to
dnl # /etc/mail/sendmail.mc, you will need to regenerate the
dnl # /etc/mail/sendmail.cf file by confirming that the sendmail-cf package is
dnl # installed and then performing a
dnl #
dnl # make -C /etc/mail
dnl #
include(`/usr/share/sendmail-cf/m4/cf.m4′)dnl
VERSIONID(`setup for Red Hat Linux’)dnl
OSTYPE(`linux’)dnl
dnl #
dnl # default logging level is 9, you might want to set it higher to
dnl # debug the configuration
dnl #
dnl define(`confLOG_LEVEL’, `9′)dnl
dnl #
dnl # Uncomment and edit the following line if your outgoing mail needs to
dnl # be sent out through an external mail server:
dnl #
undefine(`SMART_HOST’)
dnl #
define(`confDEF_USER_ID’,“8:12”)dnl
dnl define(`confAUTO_REBUILD’)dnl
define(`confTO_CONNECT’, `1m’)dnl
define(`confTRY_NULL_MX_LIST’,true)dnl
define(`confDONT_PROBE_INTERFACES’,true)dnl
define(`PROCMAIL_MAILER_PATH’,`/usr/bin/procmail’)dnl
define(`ALIAS_FILE’, `/etc/aliases’)dnl
define(`STATUS_FILE’, `/var/log/mail/statistics’)dnl
define(`UUCP_MAILER_MAX’, `2000000′)dnl
define(`confUSERDB_SPEC’, `/etc/mail/userdb.db’)dnl
define(`confPRIVACY_FLAGS’, `authwarnings,novrfy,noexpn,restrictqrun’)dnl
dnl #
dnl # The following allows relaying if the user authenticates, and disallows
dnl # plaintext authentication (PLAIN/LOGIN) on non-TLS links
dnl #
define(`confAUTH_OPTIONS’,`A’)
dnl #
dnl # PLAIN is the preferred plaintext authentication method and used by
dnl # Mozilla Mail and Evolution, though Outlook Express and other MUAs do
dnl # use LOGIN. Other mechanisms should be used if the connection is not
dnl # guaranteed secure.
dnl #
dnl # TRUST_AUTH_MECH(`DIGEST-MD5 CRAM-MD5 LOGIN PLAIN’)dnl
dnl # define(`confAUTH_MECHANISMS’, `DIGEST-MD5 CRAM-MD5 LOGIN PLAIN’)dnl
dnl #
TRUST_AUTH_MECH(`LOGIN PLAIN’)dnl
define(`confAUTH_MECHANISMS’, `LOGIN PLAIN’)dnl
dnl #
dnl #
dnl # Rudimentary information on creating certificates for sendmail TLS:
dnl # make -C /usr/share/ssl/certs usage
dnl # or use the included makecert.sh script
dnl #
dnl define(`confCACERT_PATH’,`/usr/share/ssl/certs’)
dnl define(`confCACERT’,`/usr/share/ssl/certs/ca-bundle.crt’)
dnl define(`confSERVER_CERT’,`/usr/share/ssl/certs/sendmail.pem’)
dnl define(`confSERVER_KEY’,`/usr/share/ssl/certs/sendmail.pem’)
dnl #
dnl # This allows sendmail to use a keyfile that is shared with OpenLDAP’s
dnl # slapd, which requires the file to be readble by group ldap
dnl #
dnl define(`confDONT_BLAME_SENDMAIL’,`groupreadablekeyfile’)dnl
dnl #
dnl define(`confTO_QUEUEWARN’, `4h’)dnl
dnl define(`confTO_QUEUERETURN’, `5d’)dnl
dnl define(`confQUEUE_LA’, `12′)dnl
dnl define(`confREFUSE_LA’, `18′)dnl
define(`confTO_IDENT’, `0′)dnl
dnl FEATURE(delay_checks)dnl
FEATURE(`no_default_msa’,`dnl’)dnl
FEATURE(`smrsh’,`/usr/sbin/smrsh’)dnl
FEATURE(`mailertable’,`hash -o /etc/mail/mailertable.db’)dnl
FEATURE(`virtusertable’,`hash -o /etc/mail/virtusertable.db’)dnl
FEATURE(redirect)dnl
FEATURE(always_add_domain)dnl
FEATURE(use_cw_file)dnl
FEATURE(use_ct_file)dnl
dnl #
dnl # The -t option will retry delivery if e.g. the user runs over his quota.
dnl #
FEATURE(local_procmail,`’,`procmail -t -Y -a $h -d $u’)dnl
FEATURE(`access_db’,`hash -T<TMPF> -o /etc/mail/access.db’)dnl
FEATURE(`blacklist_recipients’)dnl
EXPOSED_USER(`root’)dnl
dnl #
dnl # The following causes sendmail to only listen on the IPv4 loopback address
dnl # 127.0.0.1 and not on any other network devices. Remove the loopback
dnl # address restriction to accept email from the internet or intranet.
dnl #
dnl # DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA’)dnl
dnl #
dnl # The following causes sendmail to additionally listen to port 587 for
dnl # mail from MUAs that authenticate. Roaming users who can’t reach their
dnl # preferred sendmail daemon due to port 25 being blocked or redirected find
dnl # this useful.
dnl #
dnl DAEMON_OPTIONS(`Port=submission, Name=MSA, M=Ea’)dnl
dnl #
dnl # The following causes sendmail to additionally listen to port 465, but
dnl # starting immediately in TLS mode upon connecting. Port 25 or 587 followed
dnl # by STARTTLS is preferred, but roaming clients using Outlook Express can’t
dnl # do STARTTLS on ports other than 25. Mozilla Mail can ONLY use STARTTLS
dnl # and doesn’t support the deprecated smtps; Evolution <1.1.1 uses smtps
dnl # when SSL is enabled– STARTTLS support is available in version 1.1.1.
dnl #
dnl # For this to work your OpenSSL certificates must be configured.
dnl #
dnl DAEMON_OPTIONS(`Port=smtps, Name=TLSMTA, M=s’)dnl
dnl #
dnl # The following causes sendmail to additionally listen on the IPv6 loopback
dnl # device. Remove the loopback address restriction listen to the network.
dnl #
dnl DAEMON_OPTIONS(`port=smtp,Addr=::1, Name=MTA-v6, Family=inet6′)dnl
dnl #
dnl # enable both ipv6 and ipv4 in sendmail:
dnl #
dnl DAEMON_OPTIONS(`Name=MTA-v4, Family=inet, Name=MTA-v6, Family=inet6′)
dnl #
dnl # We strongly recommend not accepting unresolvable domains if you want to
dnl # protect yourself from spam. However, the laptop and users on computers
dnl # that do not have 24×7 DNS do need this.
dnl #
FEATURE(`accept_unresolvable_domains’)dnl
dnl #
dnl FEATURE(`relay_based_on_MX’)dnl
dnl #
dnl # Also accept email sent to “localhost.localdomain” as local email.
dnl #
LOCAL_DOMAIN(`localhost.localdomain’)dnl
dnl #
dnl # The following example makes mail from this host and any additional
dnl # specified domains appear to be sent from mydomain.com
dnl #
dnl MASQUERADE_AS(`sprinkler.com’)dnl
dnl #
dnl # masquerade not just the headers, but the envelope as well
dnl #
dnl FEATURE(masquerade_envelope)dnl
dnl #
dnl # masquerade not just @mydomainalias.com, but @*.mydomainalias.com as well
dnl #
dnl FEATURE(masquerade_entire_domain)dnl
dnl #
dnl MASQUERADE_DOMAIN(localhost)dnl
dnl MASQUERADE_DOMAIN(localhost.localdomain)dnl
dnl MASQUERADE_DOMAIN(mydomainalias.com)dnl
dnl MASQUERADE_DOMAIN(mydomain.lan)dnl
MAILER(smtp)dnl
MAILER(procmail)dnl