The rules are:

  • a single star (*) matches zero or more characters within a path name
  • a double star (**) matches zero or more characters across directory levels
  • a question mark (?) matches exactly one character within a path name

Another way to think about it is double star (*) matches slash (/) but single star () does not.

Let's say you have the files:

  1. bar.txt
  2. src/bar.c
  3. src/baz.c
  4. src/test/bartest.c

Then the patterns:

  • *.c matches nothing (there are no .c files in the current directory)
  • src/*.c matches 2 and 3
  • */*.c matches 2 and 3 (because * only matches one level)
  • **/*.c matches 2, 3, and 4 (because ** matches any number of levels)
  • bar.* matches 1
  • **/bar.* matches 1 and 2
  • **/bar*.* matches 1, 2, and 4
  • src/ba?.c matches 2 and 3