sntop: A simple, network kind of top

For as many *top programs as there are, it shouldn’t surprise me that there’s an sntop. It should surprise me that sntop is a little … different.

sntop doesn’t really poll anything local, unless you tell it to test your loopback address. Otherwise, sntop checks servers — or other addresses, like a network access point — to see if they respond. Simple enough.

And in terms of setup and output, sntop is pretty simple too. It won’t do anything until you give it a proper ~/.sntoprc file, and configuration is very straightforward — a display name, its IP and a space for comments or notes. That’s about it.

Output, as you can see above, is also fairly simple. sntop will pause until you press a key, and then recheck every server in its list.

sntop can also dump to an HTML file, and has a few command line options as well. It can refresh at interval, sound an alarm if something isn’t responding, and output to a log file.

So yes, while it is simple, it can do a lot more than just what you see above.

dhcping: Maybe the simplest yet

This will be short: As far as I can tell, this is all dhcping will do:

Not that it’s bad or somehow an underperformer. Reading through the man pages and the home page, that’s all dhcping was intended to do — check that a dhcp server is still running.

It does give the impression of a piece of a larger puzzle though. The man page says it returns either 0 or 1, reflecting the state of the server.

I’m no programmer, but methinks that could be useful in a larger application.

But alas … that’s all there is to it. Quite possibly the simplest program yet. 😉

csvkit: Lots of little tools, in a pack

I don’t work with csv files much, but I hear they are popular among those who use databases.

I have run through one or two, for example when converting from sc format to csv, for access through conventional graphical spreadsheets. That requires a little search-and-replace acrobatics, as you might expect. To that end, csvkit has some nifty tools in it.

csvclean can touch up small errors in a csv file. csvlook displays the contents in a table format, drawn with a header and ASCII lines.

csvstat can give you a breakdown of each column in a csv file, and there are csvcut, csvgrep, csvsort, csvjoin … among still others.

It seems that most of the tools have some unified flags and options; for example, the flag to declare a different delimiter in csvlook is the save in csvstat. Uniformity: That’s a good idea.

There are enough tools in here to keep the maddest scientist busy for a while, and I doubt it would take long to adopt them. If you work with csv files a lot, this might be the tool you’ve been waiting for. 😉