FreeBSD Man Pages

alphasort(3)

NAME

     scandir, alphasort -- scan a directory

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <sys/types.h>
     #include <dirent.h>

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

     int
     alphasort(const void *d1, const void *d2);

DESCRIPTION

     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
     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.

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

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), dir(5)

HISTORY

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

FreeBSD 5.4			 June 4, 1993			   FreeBSD 5.4

SPONSORED LINKS