Created attachment 492025 [details]
Allow linux to use its own getopt

Description of problem:
If one wishes to use getopt_long in the ssh program, then one is confronted with issues because openssh uses an in-tree implementation of getopt based on the BSD implementation.


Version-Release number of selected component (if applicable):
openssh-5.3p1-20.el6_0.3.x86_64


How reproducible:
Always after making a trivial (at face value) conversion to getopt_long

Steps to Reproduce:
Setting up the appropriate variables including struct option list of a single { 0, 0, 0, 0 } element, and the required index variables, then calling getopt_long instead of getopt.  None of the parameters can receive the optarg string


Actual results:
Even existing command line params that expect arguments are presented with an optarg value that is always NULL, the same goes for long options


Expected results:
optarg is not NULL, existing params receive their arguments as with getopt


Additional info:
This patch was motivated by an internal change I was making to add a custom command line flag to the ssh client.  Seeing as many single character flags are used already, I decided to use a long option to make it distinct and lessen chances of conflicts with common releases of openssh.

During openssh configure, the host system is queried for the existence of an exported variable 'optreset', which is present in the BSD c library, but not in glibc.  If not found, as it is in linux, openssh then goes an aliases the getopt function and it's associated exported variables with those found in an in-tree BSD compat implementation of getopt using C macros, this alternative implementation of getopt provides optreset.

The alternative BSD getopt provides... getopt, but it doesn't provide getopt_long, so when one invokes that, they are getting the glibc version, which treats the exported variables differently to BSD, and hilarity ensues.

My patch addressing the issue doesn't try to use getopt_long, it just allows linux to use the glibc getopt, and the glibc (and other non-BSD C libraries) method of resetting the getopt parse.  It sets the stage for one to use getopt_long if they wish.

I hope somebody can find this useful.