text: dirname - report the parent directory name of a file pathname
  #include  "." .
  This interface need not be reentrant.
  The dirname() function returns a pointer to a string that is the parent directory of path. If path is a null pointer or points to an empty string, a pointer to a string "." is returned.
  The dirname() function may modify the string pointed to by path, and may return a pointer to static storage that may then be overwritten by subsequent calls to dirname().
  No errors are defined.
  The following code fragment reads a pathname, changes the current working directory to the parent directory, and opens the file.
  char path[MAXPATHLEN], *pathcopy; int fd; fgets(path, MAXPATHLEN, stdin); pathcopy = strdup(path); chdir(dirname(pathcopy)); fd = open(basename(path), O_RDONLY);
  The dirname() and basename() functions together yield a complete pathname. The expression dirname(path) obtains the pathname of the directory where basename(path) is found.
  None.
  basename(), <libgen.h>.