Would you buy a "GNU Make Cookbook" e-book?

I've been thinking about taking all the recipes for GNU Make things that I've written over the years as articles, or blog entries, or answers to people's questions on help-make and writing them up as an e-book for purchase and download from this web site.

Here's a sample recipe in PDF format so that you can see what I'm taking about.

So, the critical questions:

1. Would you buy such a book?
2. If so, how much would you pay for it?
3. What format would be best? PDF?

John.

Comments

dirty dingus said…

I hate PDF!!! Regular HTML or RTF or plain text in decreasing order of preference

4:26 PM

Anonymous said…

I would buy and would pay US$20 or US$25 for the book

2:45 PM

Anonymous said…

postscript?

4:27 PM

Anonymous said…

Probably not, the poor level of maintanance that GNU make receives makes me think that the world is ready for a replacement.

If the book was say 80% portable recipies, 15% GNU specific, and 5% other makes, I would find it much more attractive. (I would be quite happy with the 80% portable recipies havings a GNU make sidebar saying "this is much simpler in GNU make, just do ...")

Of course it is often much more difficult to do something interesting in a portable manner.

10:02 PM

Your last name contains invalid characters

My last name is "Graham-Cumming". But here's a typical form response when I enter it:

Does the web site have any idea how rude it is to claim that my last name contains invalid characters? Clearly not. What they actually meant is: our web site will not accept that hyphen in your last name. But do they say that? No, of course not. They decide to shove in my face the claim that there's something wrong with my name.

There's nothing wrong with my name, just as there's nothing wrong with someone whose first name is Jean-Marie, or someone whose last name is O'Reilly.

What is wrong is that way this is being handled. If the system can't cope with non-letters and spaces it needs to say that. How about the following error message:

Our system is unable to process last names that contain non-letters, please replace them with spaces.

Don't blame me for having a last name that your system doesn't like, whose fault is that? Saying "Your last name …

All the symmetrical watch faces (and code to generate them)

If you ever look at pictures of clocks and watches in advertising they are set to roughly 10:10 which is meant to be the most attractive (smiling!) position for the hands. They are actually set to 10:09.14 if the hands are truly symmetrical. CC BY 2.0 image by Shinji
I wanted to know what all the possible symmetrical watch faces are and so I wrote some code using Processing. Here's the output (there's one watch face missing, 00:00 or 12:00, because it's very boring):

The key to writing this is to figure out the relationship between the hour and minute hands when the watch face is symmetrical. In an hour the minute hand moves through 360° and the hour hand moves through 30° (12 hours are shown on the watch face and 360/12 = 30).
The core loop inside the program is this: for (int h = 0; h <= 12; h++) {
float m = (360-30*float(h))*2/13;
int s = round(60*(m-floor(m)));
int col = h%6;
int row = floor(h/6);
draw_clock((r+f)*(2*col+1), (r+f)*(row*2+1), r, h, floor(m…

Importing an existing SSL key/certificate pair into a Java keystore

I'm writing this blog post in case anyone else has to Google that. In Java 6 keytool has been improved so that it now becomes possible to import an existing key and certificate (say one you generated outside of the Java world) into a keystore.

You need: Java 6 and openssl.

1. Suppose you have a certificate and key in PEM format. The key is named host.key and the certificate host.crt.

2. The first step is to convert them into a single PKCS12 file using the command: openssl pkcs12 -export -in host.crt -inkey host.key > host.p12. You will be asked for various passwords (the password to access the key (if set) and then the password for the PKCS12 file being created).

3. Then import the PKCS12 file into a keystore using the command: keytool -importkeystore -srckeystore host.p12 -destkeystore host.jks -srcstoretype pkcs12. You now have a keystore named host.jks containing the certificate/key you need.

For the sake of completeness here's the output of a full session I performe…

John Graham-Cumming

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