(If using netscape, shift-click a link to download it to a file.)


Gulp: Lossless Gigabit Remote Packet Capture with Stock Linux on Ordinary PC Hardware
If you thought linux was inept at capturing packets because Tcpdump and WireShark drop lots of packets, think again! New software, named Gulp, can capture a gigabit/sec on ordinary/modest PC hardware running stock linux and write it all to disk dropping NO packets. The tricks, writeup, source code, manpage, limitations (and suggested enhancements to linux) are all available at the Gulp Homepage.

As an added bonus, Gulp can capture and decapsulate Cisco's "Encapsulated Remote SPAN ports" allowing (authorized) mirroring and capturing of packets from "anywhere" on a campus network (anywhere the router can be configured to send them).

New-patches - Find appropriate RedHat patches.
This script makes it easier to keep your system up-to-date and secure. It is older and less automated than yum but gives you somewahat more control. It finds relevant patches and presents them in a format that RPM (the Redhat Package Manager) can use to install them. Instructions for use are at the beginning of the script and in this manpage source or html or text. If you're on campus, the new-patches link will customize the script for use on campus, if possible. If you're off campus, I don't presume to know which mirror site would be best for you but I still strongly recommend you pick one from this list of Fedora mirrors or this list of Fedora Legacy mirrors.

RPM can automatically download patches over the network, so the use of get-patches with the new-patches script above is entirely optional. If, however, you prefer to download the patches to local disk once and then install them, this script should do the trick.

Tiny (33-Line) Unix Shell Script Web Server.

Trivial to setup and configure, serves files and directories at speeds acceptable for light use.

Spell-check macros for use with the VI editor.

Ip2name: address to name translator and name2ip: name to address translator

ip2name looks up hostnames for any/all IP addresses found in input and appends or replaces as per command line options. name2ip does pretty much the reverse. See ip2name manpage source or manpage text.

Barplot shell/awk script for simple character barplots like this example...

Demonstrates use of the shell to process command-line arguments and pass them into an awk script.

Expand and sort crontab into a timeline.

This script makes it easier to figure out what runs at a given time.

Nuniq: similar to "sort -u" but preserves input order.

Keep only the most recent of all input lines with a unique value in a field. See the manpage source or html.

Datesort: sort Day and Month names temporally.

This script allows you to sort day-of-week (Sun, Mon, etc.) and month names (Jan, Feb, etc.) temporally rather than alphabetically. See the manpage source or html. Note: Gnu "sort -M" can do the month name part of this.

Psort: sort 2-digit years.

This script sorts lines beginning with a 2-digit year (such as yymmdd) using a pivot-point of 1970. See also the manpage.

Sumx: column summer.

This script with many options sums (or deltas) columns of input numbers (or times) in various ways. See the manpage source or html.

Ror: rotate columns right.

This will take the last column and rotate it to be the first column, moving the others to the right. (For example, a time delta appended by sumx above will be moved to the beginning of the line).

Unstab: see what your C code generates.

Puts C source code into generated assembly language for easier reading. See manpage source or html for usage and example output.

Bold2html.

Convert bold and underline sequences for a terminal (such as from "man" or "wdiff -p") into color html which looks similar in a web browser. Usage options are at the start of the script and here is some sample output.

Asis: a pre-inverse of nroff.

To insert pre-formatted text into an nroff or troff (or groff) document (such as a manpage) filter it through this first.

Tx: title extract.

Print first line(s) and filter remainder with specified command. For example:  "ps aux | tx grep bash " will show both the first (heading) line of "ps" output and subsequent lines containing the word "bash". Without "tx", the heading would be missing.

Mpx: audio file multiplexor.

A shell script to play two audio files simultaneously (in sync), switching at will between them. This is ideal for comparing two versions of an audio file (such as an MP3 and its original WAV). With slight changes, could multiplex other kinds of data.

Tcpdump-unhd: highlight data in tcpdump output.

Postprocess "tcpdump -x" output, highlighting TCP data. See the manpage: source or html.

Amusing Text Scrambler.

See comments at the beginning of the script. With suitable input, can produce very funny results. For example...

Pipe into VI: Use the VI editor as a pager.

If you have VIM version 5 or greater, use "vim -" instead.

Make a table from columns of label/value pairs.

"Missing" values are handled properly. For more info, see the manpage source or html.

Plot a table such as produced by make-table.

For more info, see the manpage source or html.

Make directory and all intermediates For example:  md /tmp/a/b/c/d/e

I did this to prove it was possible when someone claimed it wasn't. On some systems, "mkdir -p" will do this.

Unix/perl4 trick to open a file with O_APPEND

Allows multiple processes appending to a single file to work properly.

PostScript N-upper.

Well-behaved multipage PostScript documents which "conform to Adobe document structuring conventions" can be sliced and diced and recombined with several logical pages on each physical page and/or with page order changed. For more info, see the manpage.

Inter-Core-Micro-Benchmark.

A linux microbenchmark capable of measuring inter-core data transmission overhead and helping determine which CPU cores operate most efficiently together.

More Tools