|SCANDIR(3)||Library Functions Manual||SCANDIR(3)|
scandir(const char *dirname,
struct dirent ***namelist, int
(*select)(const struct dirent *), int (*compar)(const
struct dirent **, const struct dirent **));
struct dirent **d1, const
struct dirent **d2);
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 parameter 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 directory entries will be
The compar parameter 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.
alphasort() function is a routine
which can be used for the compar parameter to sort the
The memory allocated for the array can be deallocated with free(3), by freeing each pointer in the array and then the array itself.malloc(3) cannot allocate enough memory to hold all the data structures. directory(3), malloc(3), qsort(3), dir(5)
alphasort() functions conform to IEEE Std 1003.1-2008 (“POSIX.1”).
alphasort() functions appeared in 4.2BSD.
The argument types for
alphasort() and for
compar() argument to
scandir() were originally void
*, then changed to const void *, and then
finally changed by IEEE Std 1003.1-2008
(“POSIX.1”) to their current form of
const struct dirent **. Similarly, the
select() argument to
scandir() was originally struct
dirent * until it was changed to its current form of
const struct dirent *.
|February 28, 2015||OpenBSD-current|