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scandir(3)
NAME
  scandir, alphasort - Scan or sorts directory contents

SYNOPSIS
  #include <sys/types.h>
  #include <sys/dir.h>

  int scandir(
	  char *dir_name,
	  struct dirent *(*name_list []),
	  int (*compare)(struct dirent **dir1, struct dirent **dir2) );

  int alphasort(
	  struct dirent **dir1,
	  struct dirent **dir2 );

LIBRARY
  Standard C Library (libc)

PARAMETERS
  dir_name
      Points to the directory name.

  name_list
      Points to the array of pointers to directory entries.

  select
      Points to a user-supplied function that is called by the scandir()
      function to select which entries to include in the array.

  compare
      Points to a user-supplied function that sorts the completed array.

  dir1
      Points to a dirent structure.

  dir2
      Points to a dirent structure.

DESCRIPTION
  The scandir() function reads the directory pointed to by the dir_name
  parameter. It then uses the malloc() function to create an array of
  pointers to directory entries. The scandir() function returns the number of
  entries in the array and, through the name_list parameter, a pointer to the
  array.

  The select parameter points to a user-supplied function that the scandir()
  function calls to select which entries to include in the array. The
  selection routine is passed a pointer to a directory entry and returns a
  nonzero value for a directory entry that is included in the array. If the
  select parameter is a null value, all directory entries are included.

  The compare parameter points to a user-supplied function that is passed to
  the qsort() function to sort the completed array. If the compare parameter
  is a null value, the array is not sorted.

  The memory allocated to the array can be deallocated by freeing each
  pointer in the array, and the array itself, with the free() function.

  The alphasort() function alphabetically compares the two dirent structures
  pointed to by the dir1 and dir2 parameters. This function can be passed as
  the compare parameter to either the scandir() function or the qsort()
  function. A user-supplied subroutine may also be used.

RETURN VALUES
  The scandir() function returns -1 if the directory cannot be opened for
  reading or if the malloc() function cannot allocate enough memory to hold
  all the data structures. If successful, the scandir() function returns the
  number of entries found.

  The alphasort() function returns the following values:

    ·  Less than 0 (zero): The dirent structure pointed to by the dir1
       parameter is lexically less than the dirent structure pointed to by
       the dir2 parameter.

    ·  0 (zero): The dirent structures pointed to by the dir1 parameter and
       the dir2 parameter are equal.

    ·  Greater than 0 (zero): The dirent structure pointed to by the dir1
       parameter is lexically greater than the direntstructure pointed to by
       the dir2 parameter.

SEE ALSO
  Functions: malloc(3), opendir(3), qsort(3)

Index for Section 3

Alphabetical listing for S

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