Unix/Linux

xtail watches the growth of files. It's like running a tail -f on a bunch of files at once. My favorite usage is:

$ xtail /var/log/*

You can specify both filenames and directories on the command line. If you specify a directory, it watches all the files in that directory. It will notice when new files are created (and start watching them) or when old files are deleted (and stop watching them).

The xtail program has been around for a long time. O'Reilly & Associates even included it in their Unix Power Tools book. A link to the 1989 release is included below. The 3B2 sitting in your cellar would love a copy.

19 Feb 2012 Update - I've included patches (to the 2.1 release) from Jari Aalto below, as 20120219-patch-aalto.zip. I've not reviewed the patches. Jari's patches include a fix for SIGQUIT under Cygwin, as well as some Debian patches.

uucpm provides networked "Unix-to-Unix Copy" (uucp) services on ancient systems that do provide TCP/IP networking support, but otherwise lack this capability. This includes systems such as SCO Xenix and NCR Towers.

The package includes two programs. The uucpm daemon converts a pseudo-tty (pty) into a device that can communicate across a TCP/IP network. A System V.2-ish port of the BSD uucpd daemon also is included. These two daemons implement, respectively, the originating and answering portions of the transfer

The rlytest utility tests a host to determine whether it will relay third-party email. It will try to relay an email message to yourself through that host. A host that allows third-party relay is subject to attack by Internet vandals, and frequently is hijacked by spammers to relay massive amounts of junk email. A host that allows third-party relay should be immediately secured, disconnected, or shunned as a menace to the Internet.

pxytest is a command line utility to test a host for open proxies that are vulnerable to spammer abuse. It is written in perl.

Unsecured proxies can be a conduit of spam. This is a particularly vexing problem, because open proxies, unlike open mail relays, hide the origin of the spam, making it impossible to trace. This utility
tests a host to see if it is vulnerable to such abuse.

enh-du is a highly-portable, high-performance, POSIX-conformant reimplementation of the du command. It has some nice features to help you better understand where all that disk space is going. If you find your current system du is buggy or unacceptably slow, or if you find some of the added features appealing, you might want to try this. You will not suffer a performance penalty to get these new features. This version probably compares well with the version of du your vendor ships.

2008 Update: The issues addressed by this package are all resolved most current releases of du.

The cgi-postin utility processes data generated from a World-Wide Web form. It is a standalone processor that may be run easily from sh, perl, or Tcl scripts.

Note: I recommend this tool only when implementing CGIs as shell scripts. For other languages, there are more modern and suitable tools for the task of CGI processing. For CGI processing in perl, I recommend the bundled CGI.pm module. For C, there are a number of packages available to do the task.

Some organizations, such as the MAPS RBL and MAPS DUL, publish lists that identify potential sources of spam and email abuse. The blq utility is a Perl script that queries one or more of these lists to determine if a particular host is listed.

It works something like this ...

The web-chpass utility allows users to change their account password through the web. This package was written with security as the foremost concern, flexibility next. It runs on systems that use PAM to manage user authorizations.

The web pages produced are completely customizable. The chpass.cgi utility contains no HTML. Instead, web pages are produced from an external template.

"Bad password" checking can be optionally enabled. The distributed web page template offers the user a choice, with these checks enabled by default.