Implement .gitignore behavior in a shell script?

I am writing a shell script that syncs files and I want to give users the ability to exclude certain files from syncing by creating a file .syncignore

that looks like a Git file .gitignore

. According to the gitignore documentation and my own experiments, these exclusion rules are more complex than a simple glob match. Some examples:

• If you have it foo
  
  in your file .gitignore
  
  , it excludes foo
  
  appearing anywhere in the path (for example ./foo
  
  , ./bar/foo
  
  and ./bar/foo/baz
  
  will be excluded), but not partial matches foo
  
  (for example ./foobar
  
  , ./bar/foobar/baz
  
  NOT excluded).
• If you include the forward slash, then the rule applies to the current directory. For example, if you have /foo
  
  in your file .gitignore
  
  , this excludes ./foo
  
  , but not ./bar/foo
  
  .
• You can include wildcards. For example, foo*
  
  excludes ./foo
  
  , ./foobar
  
  and ./bar/foobar/baz
  
  .

Is there an easy way to replicate the exception rules for .gitignore

in a shell script on OS X?