freebsd man page for alphasort

SCANDIR(3)						   BSD Library Functions Manual 						SCANDIR(3)

NAME
     scandir, alphasort -- scan a directory

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <dirent.h>

     int
     scandir(const char *dirname, struct dirent ***namelist, int (*select)(const struct dirent *),
	 int (*compar)(const struct dirent **, const struct dirent **));

     int
     scandir_b(const char *dirname, struct dirent ***namelist, int (*select(rp(const struct dirent *),
	 int (^compar)(const struct dirent **, const struct dirent **));

     int
     alphasort(const struct dirent **d1, const struct dirent **d2);

DESCRIPTION
     The scandir() function reads the directory dirname and builds an array of pointers to directory entries using malloc(3).  It returns the num-
     ber 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 included.

     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 using strcoll(3).

     The memory allocated for the array can be deallocated with free(3), by freeing each pointer in the array and then the array itself.

     The scandir_b() function behaves in the same way as scandir(), but takes blocks as arguments instead of function pointers and calls qsort_b()
     rather than qsort().

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

SEE ALSO
     directory(3), malloc(3), qsort(3), strcoll(3), dir(5)

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

BSD
								  January 3, 2010							       BSD