Unknown options in the command line arguments are passed to sh. I have seen that you want to make it use commander.c but I think that there is no need to do that for this specific issue.
fixed: handle unknown options
Added: option to clear the screen
Fixed: non integer count will not be accepted anymore
Merge branch 'master' of https://github.com/echaouchna/watch
Fixed: clear screen only when the standard output is used
Fixed: return if command not found
Added: debug mode to the makefile
Fixed: code refactoring
Add the Codeship status image
this is optional, it was added for personal testing purpose.
what's the difference here? why not just make watch?
-g option will add debugging information to the program (further reading here https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gcc/Debugging-Options.html#Debugging-Options)