1tail (basename) of 'a/b/c' is 'c' 2tail (basename) of 'def' is 'def' 3tail (basename) of 'a.b.c' is 'a.b.c' 4tail (basename) of 'a.b/c' is 'c' 5tail (basename) of 'a' is 'a' 6tail (basename) of 'a.a' is 'a.a' 7tail (basename) of '.gitignore' is '.gitignore' 8tail (basename) of 'a' is 'a' 9tail (basename) of 'a.a' is 'a.a' 10tail (basename) of 'trailing/' is '' 11exit status 0 12