This article will show you how to use the built in command line parser
that comes with the APR. There will be two source files, one showing
you how to use apr_getopt just to parse simple, single options and the
other peace of source will show you how to use it with so called long
options. You can download the single option parser here and the
long options parser here.
X NOTE: The program supplied should actually use
apr_app_initialize(&argc, &argv, NULL); since
apr_initialize() is intended for library use only.
Like everytime, you need to have APR libraries installed in order to be able to use them. You’ll additionally need the header files too, so if you’re installing from some distribution specific mechanism, be sure to have the “-dev” packages installed as well.
There is really not that much to explain this time. We first
initialize APR, create a pool, then initialize the getopt parser and
then we’re walking through the options specified on the command
line. The most notable part here is the line:
= 1;. Setting the interleave to one allows us to have options and
final arguments specified “wildly” on the command line. That means
that the order of argument is not relevant. You can specify
./aprGetoptLong --choose what -h lalalal or you can type:
./aprGetoptLong --choose what lalala -h which, in this case would
lead to the same result.
Simple options code
Now that you have seen how it works with simple options, long options is no more magic. You just have to additionally initialize an array basically, but see for yourself.
Long options code
Hope you enjoyed it.