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Tech Stuff - Survival Guides

We forget stuff - frequently. These survival guides are meant as quick (some of them are pretty long) and dirty (no smut) overviews of various, mostly open-source, software that we use on both Linux and FreeBSD and, depending on the software, occasionally on Windows. While some may call this kind of thing a cheat-sheet we prefer the term survival guide since it plays to our sense of the dramatic and on more than one occasion was only a modest exaggeration.

If this stuff is useful - we will all be very happy. If it is not useful - well that's just too bad. Though if we do miss something obvious you could drop us an email.

The general style of each guide is to describe the basic functions - locations, logging, configuration files, basic commands and the occasional weird stuff (it seemed important at the time) and then link to more detailed sources where appropriate.

Digital Audio The beginning of a new section on digital audio - since the field is enormous these pages are a mere splash in the ocean. But they make a nice sound. Equalization. Glossary. Frequencies and harmonics, digital sound primer, acoustic calculator. And some other stuff even we forget.
Cron Scheduling a task seems to be a simple enough process - but it quickly gets real confusing 'cos of all the features and options. Covers FreeBSD and Linux (Fedora Core).
Cryptography Overviews and tutorial material on Cryptography, Authentication, Authorization, Hashes, Digests, MAC, digital signatures and other eye-popping, headache inducing stuff. But not a drop of Math on the page.
SSL/TLS/X.509 All you never wanted to know about SSL/TLS and X.509 certificates - including generating self-signed certificates with OpenSSL. Gruesome stuff. Take a couple of days off after reading this section. Be warned this page is huge (or should that be yuuuge).
ASN.1 and DER Ghastly stuff. We always felt guilty when looking at those ASN.1 SEQUENCE...SET...CHOICE snippets that are scattered all over the LDAP/X.509/PKI RFCs. We vaguely understood what they did. Then we had to write a DER decoder and vaguely was no longer acceptable. After numerous blind alleys we finally got there. This dreadful, mind-numbing page may help you get there faster. There again, it may not. Explanations based on a worked example of an X.509 certificate.
FreeBSD Update Information about upgrading FreeBSD, keeping it up to date using the superb freebsd-update, updating ports and if you are into ruby whether to use ports or RubyGems to keep up to date.
Kerberos Kerberos V. The only network authentication (and authorization) protocol in town. As used in Active Directory (AD). And GSSAPI. We feel a headache coming on.
Memory Jogger on Decimal, Hex and Binary Pretty stupid page but we get frequent email on the topic so this mercifully short page was the result. Also covers the joys of Bit Numbering conventions and that MSB and LSB stuff.
MySQL The ever popular MYSQL. Good Database software but operationally a bit confusing. IOHO. Pretty long in the tooth page these days. We don't keep it updated. Moved on to newer SQL pastures.
NT LAN Manager Some information on NT LAN Manager that we collected some years ago for a Samba PDC project. We were trying to understand LAN Manager. Bad mistake.
Postfix Postfix SMTP Agent. We use Postfix in combination with Dovecot as the Mail agent (with Squirrelmail for web mail access). Includes configuring virtual_mailbox_domains, virtual_alias_domains, TLS, spamassasin, amavis, greylisting, spf, piping mail to scripts and some UCE controls.
sed Sed is incredibly useful and brutally complex. Some notes on its uses and links to other material on our page introducing regular expressions.
wxWidgets We had an 'up close and personal' encounter recently with wxWidgets (2.8.10). Gobs of documentation. Really superb job. However, we couldn't find anything on tooltips, menus and context menus (a.k.a. popup menus). Bound to be there. But where? This page was the result.
Java A recent project forced us to use Java. There are a ton of resources on the web for Java developers. Hugely reduced our learning curve (as C/C++ guys). However, we could find no solution to intercepting editing in HTML forms. And then we needed to force the Submit button. Stubborness found solutions as documented on this page. Also we took the opportunity to develop a simple (read limited) (X)SSI (Apache extended includes) expansion utility to allow HTML files with (X)SSI to be exported to non-(X)SSI supporting web servers or for use with HTML viewers.

Problems, comments, suggestions, corrections (including broken links) or something to add? Please take the time from a busy life to 'mail us' (at top of screen), the webmaster (below) or info-support at zytrax. You will have a warm inner glow for the rest of the day.

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