FreeBSD 7.0 manual page repository

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scandir, alphasort - scan a directory



      scandir, alphasort - scan a directory


      Standard C Library (libc, -lc)


      #include <sys/types.h>
      #include <dirent.h>
      scandir(const char *dirname, struct dirent ***namelist,
              int (*select)(struct dirent *),
              int (*compar)(const void *, const void *));
      alphasort(const void *d1, const void *d2);


      The scandir() function reads the directory dirname and builds an array of
      pointers to directory entries using malloc(3).  It returns the number of
      entries in the array.  A pointer to the array of directory entries is
      stored in the location referenced by namelist.
      The select argument is a pointer to a user supplied subroutine which is
      called by scandir() to select which entries are to be included in the
      array.  The select routine is passed a pointer to a directory entry and
      should return a non-zero value if the directory entry is to be included
      in the array.  If select is null, then all the directory entries will be
      The compar argument is a pointer to a user supplied subroutine which is
      passed to qsort(3) to sort the completed array.  If this pointer is null,
      the array is not sorted.
      The alphasort() function is a routine which can be used for the compar
      argument to sort the array alphabetically.
      The memory allocated for the array can be deallocated with free(3), by
      freeing each pointer in the array and then the array itself.


      Returns -1 if the directory cannot be opened for reading or if malloc(3)
      cannot allocate enough memory to hold all the data structures.
      directory(3), malloc(3), qsort(3), dir(5)


      The scandir() and alphasort() functions appeared in 4.2BSD.


Based on BSD UNIX
FreeBSD is an advanced operating system for x86 compatible (including Pentium and Athlon), amd64 compatible (including Opteron, Athlon64, and EM64T), UltraSPARC, IA-64, PC-98 and ARM architectures. It is derived from BSD, the version of UNIX developed at the University of California, Berkeley. It is developed and maintained by a large team of individuals. Additional platforms are in various stages of development.