Bitcoin and Cryptocurrency Technologies

By | April 25, 2016

By Arvind Narayanan, Joseph Bonneau, Edward Felten, Andrew Miller, Steven Goldfeder. A wonderful free book in pdf format that explains lots of different concepts very clearly with great examples. If there were “answers” to the exercises at the end of each section it would be been even better. The best part was the way the… Read More »

Mac OSX fatal error: ‘openssl/sha.h’ file not found

By | April 19, 2016

If you have come across this sha.h not found error on a Mac, it is because Apple dropped support for openssl. Apple deprecated its OpenSSL shared libraries a while back (with OS X 10.7). That’s because OpenSSL doesn’t offer release-to-release binary compatibility, so we can’t update the shared libraries to the latest OpenSSL without breaking… Read More »

Category: OSX

What exactly is a bitcoin address?

By | April 8, 2016

At a high level, a bitcoin address comprises of 256 1’s and 0’s pushed through some algorithms to result in a ~34 character string that can be given out to receive funds. That’s the short version. Here is the long version. What does a bitcoin address look like? Here is a sample bitcoin address: “18BgGGrBms3eGCRj2Vvrxso4XzWjJEEMBv” A… Read More »

An array of pointers or a pointer of arrays?

By | April 7, 2016

There is a very subtle difference in the following: int *myarray[10] v’s int (*myarray)[10] The first declaration is interpreted as an array of 10 integers, that are pointers. That is you have 1 array holding 10 pointers that are of type integer. The square brackets have a higher precedence so the myarray[10] gets defined first.… Read More »

Why is the GNU software manual so hard to read?

By | March 11, 2016

I was researching on  what “dnl” meant within a configure.ac file and my Google search showed results from http://www.gnu.org/software/m4/manual/m4-1.4.14/html_node/Dnl.html. Thinking this was the authoritative source, upon reading, I couldn’t for the life of me understand it. After searching some more, it was explained very clearly and succinctly at Stack Overflow of all places. http://stackoverflow.com/questions/3371239/autoconf-dnl-vs In configure.ac, lines commented with… Read More »