Here is a collection of software, online tools, and other fundamental information that are often useful.

Some scripts

Installer script,, installs these scripts to /usr/local/bin on your system.

If you trust this site, you can install everything by simply going

        wget -O - | sh

No-comment script,, displays a file or STDIN without "#"-comments or blank lines.

This simple script is very handy for displaying Unix configuration files on one screen instead of having to paginate. Examples of usage:

        nocomment httpd.conf
        cat httpd.conf | nocomment

Substitution script,, substitutes strings in files and reports how many changes were made in each file.

While it is easy enough to do in-place substitutions as a one-liner in sed or perl (e.g. sed -i 's/stringtofind/replacement/g' file-to-fix or perl -p -i -e 's/stringtofind/replacement/gs' file-to-fix), it is handy to have a short command to do this common task plus a few other tricks. Use backslash to escape slashes. Set the environmental variable PRESERVE_TIME=1 to do substitutions without touching the modification times of the files. Examples of usage:

        sub 'mIstake' 'Correction' letter1.txt letter2.txt
        sub 'local\/bin' 'local\/sbin' Makefile
        PRESERVE_TIME=1 sub 'footor' 'footer' *.html

Service script,, is a simple wrapper script around the standard SysV /etc/init.d scripts which manage service startup on most Unix-type systems.

This simple script can save your sanity if you sometimes have to explain to a non-Unix administrator over a telephone how to restart a service. Instead of screaming forwardslash-e-t-c-forwardslash-i-n-i-t-dot-d-forwardslash-a-p-a-c-h-e-two-space-r-e-s-t-a-r-t, NO! I SAID "FORWARDSLASH"! ARRRGH!, you can simply tell them:

        service apache2 restart

Online tools

What Is My IP,, allows you to rapidly check your IP as viewed by machines on the Internet. Open Port Check Tool,, allows you to rapidly verify that ports for any services you offer from your IP (eg. web server, mail server, etc.) are reachable by machines on the Internet.

Speedtest by Ookla,, useful for checking that your ISP is giving you what you paid for. It can also reveal that the traffic-shaping software on your firewall/router is activated/misconfigured.

Bandwidth Test at,, is the same as above, except offered by VTX.

EICAR test virus,, is a harmless .COM executable that is used as a standard anti-virus test case. If your web-proxy blocks this file, you know that the anti-virus mechanism in the proxy is working. This file was copied from

Virus Total,, is a multi-engine anti-virus checker. This is useful for double-checking any bizarre results (e.g. false-positives for software that you are almost certain about) that your normal AV engine might be giving you.

MultiRBL,, allows you to rapidly check an IP on many popular and obscure blacklists simultaneously. This is an important test when your mail is not getting through for some reason.

mail-tester,, allows you to rapidly check the correctness (or spaminess) of emails sent from your mail server. Good to try when Gmail or Yahoo are rejecting your emails and they refuse to explain exactly why.

Phenoelit default password list,, extremely useful when you have lost the documentation for a mystery box or the local sysadmin has been run over by a bus.

Service status of various providers:, VTX, Cablecom, Swisscom

SSL Labs checker,, allows you to check a the SSL/TLS encryption of a web server and explains where the problems are.

Secure Email checker,, allows you to check a the TLS encryption of a SMTP server and explains where the problems are.

Fundamental information

SWINOG, the Swiss Network Operators Group, maintains a mailing list where one can learn the status of Swiss and world-wide networks from the people who know: the providers' network gurus. The mailing-list achives are at

The Linux Consultants Guide at is probably the best community-maintained database of companies and individuals offering Linux-related support. Currently (February 2011) there are over 40 entries for Switzerland.

The GULL, Groupe Romand des Utilisateurs de Linux et des Logiciels Libres, at is a good starting point for meeting members of the free-software community of the French-speaking part of Switzerland (Genève, Vaud, Valais, Neuchâtel, Fribourg, Jura, Bern). Most activities are facilitated by the Internet, particularly the support and commercial mailing lists at

The Wikipedia List of TCP and UDP port numbers is sometimes better than /etc/services or Nmap's nmap-services because it also lists unofficial and conflicted port numbers. This information saves time when you are trying to decipher firewall log messages.