cjdns/doc/notes/do.md

What happens when you call './do'

do is a bash script, and is therefore at least somewhat readable by humans.

The script starts off by initializing some variables:

• The output of uname is trimmed and assigned to the environment variable PLATFORM
• The output of uname is then piped through sed to replace 'i' and another character with 'x', such that i686 becomes x86. The returned value is assigned to the environment variable MARCH. Architectures like x86_64 are unaffected
• The environment variable BUILDDIR is initialized to equal "build_${PLATFORM}
• The environment variable NODE_MIN_VER is initialized to equal "v0.8.15"

Function Definitions

• hasOkNode Checks to see if your version of nodejs (if any) is sufficient for the build tasks. If it does, then it should (as a side effect) initialize the environment variable NODE to equal the path to your nodejs executable.
• getNode Fetches an up to date version of nodejs.
• die prints an error and kills the script.
• getsha256sum finds a working sha256sum program. It tries a number of options, and returns 0 if none are successful.
• main The main function, which I'll describe below.

Call main

The main function starts by changing into the directory with a name equivalent to the output of `"$(dirname $0)". If that fails, then the process dies with the argument "failed to set directory".

Next, we create the build directory (if it does not exist). If this fails, the process dies with the error "failed to create build dir ...".

Next, we call getsha256sum. If its output is falsey, then the script dies with the error "couldn't find working sha256 hasher"

Next, we call hasOkNode. If this returns 0, then we call getNode, if this is unsuccessful, then the script dies with the error "could not get working nodejs impl".

Finally, we use the environment variable $NODE to call cjdns/node_build/make.js with the arguments "${@}".