How do I check for valid Git branch names?

Question

I\'m developing a git post-receive hook in Python. Data is supplied on stdin with lines similar to

ef4d4037f8568e386629457d4d960915a85da2ae 61a4         


        

Answer 1

There's no need to write monstrosities in Perl. Just use /x:

# RegExp rules based on git-check-ref-format
my $valid_ref_name = qr%
   ^
   (?!
      # begins with
      /|                # (from #6)   cannot begin with /
      # contains
      .*(?:
         [/.]\.|        # (from #1,3) cannot contain /. or ..
         //|            # (from #6)   cannot contain multiple consecutive slashes
         @\{|           # (from #8)   cannot contain a sequence @{
         \\             # (from #9)   cannot contain a \
      )
   )
                        # (from #2)   (waiving this rule; too strict)
   [^\040\177 ~^:?*[]+  # (from #4-5) valid character rules

   # ends with
   (? ".($branch =~ $valid_ref_name)."\n";
}

Joey++ for some of the code, though I made some corrections.