scandir

man  scandir, 有著令人畏懼的 ***, 沒有範例的話還真不知道怎麼用。

NAME
       scandir, alphasort, versionsort - scan a directory for matching entries

SYNOPSIS
       #include

       int scandir(const char *dirp, struct dirent ***namelist,
              int (*filter)(const struct dirent *),
              int (*compar)(const struct dirent **, const struct dirent **));

       int alphasort(const void *a, const void *b);

       int versionsort(const void *a, const void *b);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       scandir(), alphasort(): _BSD_SOURCE || _SVID_SOURCE
       versionsort(): _GNU_SOURCE

DESCRIPTION
       The scandir() function scans the directory dirp, calling filter() on each directory entry.  Entries for which filter() returns non-zero are stored in strings allocated via mal‐
       loc(3), sorted using qsort(3) with the comparison function compar(), and collected in array namelist which is allocated via malloc(3).  If  filter  is  NULL,  all  entries  are
       selected.

       The  alphasort()  and  versionsort()  functions  can be used as the comparison function compar().  The former sorts directory entries using strcoll(3), the latter using strver‐
       scmp(3) on the strings (*a)->d_name and (*b)->d_name.


EXAMPLE
       #define _SVID_SOURCE
       /* print files in current directory in reverse order */
       #include

       int
       main(void)
       {
           struct dirent **namelist;
           int n;

           n = scandir(".", &namelist, 0, alphasort);
           if (n < 0)
               perror("scandir");
           else {
               while (n--) {
                   printf("%s\n", namelist[n]->d_name);
                   free(namelist[n]);
               }
               free(namelist);
           }
       }