DISCLAIMER: There is no guarantee that anything here is safe to use. Use at your own risk.
Miscellaneous things I have cooked up.

This patch adds this option to cut from GNU Coreutils.

"-z, --squeeze-delimiters treat consecutive delimiters as one"

This is a linked list implementation, suitable for drop in compilation into your sources. I find it usefull. You may find it naive incomplete and buggy. Enjoy.

This is a traceroute program I saw referenced in nanog material.

Printline is a program I use for scripts to selectively print its input lines. In its simplest form it may be used to loop your input one line at a time. Of course you could use read for at least some of this programs functionality.

Spool-remailer is a program written primarily to be used for remailing mbox spool files to users who have moved from a server before downloading their email. Of course, this was before I saw formail(1) which is pretty much a feature superset of this program for more general tasks.