SCANDIR(3)                     Library Routines                     SCANDIR(3)

NAME

       scandir, alphasort - scan a directory

SYNOPSIS

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

       int  scandir (const char *dirname, struct dirent ***namelist, int (*se���
       lect) (struct dirent *), int (*compar) (const void *, const void *));

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

       int alphacasesort (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  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 the directory entries will
       be included.

       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.

       The alphasort function is a routine which can be used  for  the  compar
       parameter to sort the array alphabetically.

       The alphacasesort function is similar to alphasort, but can be used for
       sorting in a case-insensitive manner, and is useful for the case-insen‐
       sitive filesystems used by GNO.  This function is specific to GNO.

       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  mal����
       loc(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.



GNO                             27 January 1997                     SCANDIR(3)