SCANDIR(3,L)                AIX Technical Reference                SCANDIR(3,L)



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scandir



PURPOSE

Scans a directory.

LIBRARY

Standard C Library (libc.a)

SYNTAX

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

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

DESCRIPTION

The scandir subroutine reads the directory pointed to by dirname, then uses the
malloc subroutine to create an array of pointers to directory entries.  The
scandir subroutine returns the number of entries in the array and, through the
namelist parameter, a pointer to the array.

The select parameter points to a user-supplied subroutine that is called by
scandir to select which entries to include in the array.  The selection routine
is passed a pointer to a directory entry and should return a nonzero value for
a directory entry that is included in the array.  If select is NULL, all
directory entries are included.

The compar parameter also points to a user-supplied subroutine.  This routine
is passed to qsort to sort the completed array.  If compar is NULL, the array
is not sorted.  The alphasort subroutine provides comparison functions for
sorting alphabetically and can be specified by the compar parameter.  (See
"alphasort.")

The memory allocated to the array can be deallocated by freeing each pointer in
the array and the array itself, with the free subroutine.  (For more
information on free, see "malloc, free, realloc, calloc, valloc, alloca,
mallopt, mallinfo.")

RETURN VALUE

The scandir subroutine returns the value -1 if the directory cannot be opened
for reading, or if the malloc subroutine cannot allocate enough memory to hold



Processed November 7, 1990       SCANDIR(3,L)                                 1

SCANDIR(3,L)                AIX Technical Reference                SCANDIR(3,L)



all the data structures.  If successful, the scandir subroutine returns the
number of entries found.

RELATED INFORMATION

In this book:  "alphasort,"  "directory: opendir, readdir, telldir, seekdir,
rewinddir, closedir,"  "malloc, free, realloc, calloc, valloc, alloca, mallopt,
mallinfo," "qsort," and  "dir."















































Processed November 7, 1990       SCANDIR(3,L)                                 2