SCANDIR(3C) Standard C Library Functions SCANDIR(3C)

NAME

scandir, alphasort - scan a directory

SYNOPSIS

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

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


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

DESCRIPTION

The scandir() function reads the directory dirname using readdir(3C) and
builds an array of pointers to directory entries using malloc(3C). The
namelist argument is a pointer to an array of structure pointers. The
select argument is a pointer to a routine that is called with a pointer
to a directory entry and returns a non-zero value if the directory entry
is included in the array. If this pointer is NULL, then all the directory
entries are included. The dcomp argument is a pointer to a routine that
is passed to qsort(3C), which sorts the completed array. If this pointer
is NULL, the array is not sorted.


The alphasort() function can be used as the dcomp() function parameter
for the scandir() function to sort the directory entries into
alphabetical order, as if by the strcoll(3C) function. Its arguments are
the two directory entries to compare.

RETURN VALUES

The scandir() function returns the number of entries in the array and a
pointer to the array through the namelist argument. When an error is
encountered, scandir() returns -1 and errno is set to indicate the error.


The alphasort() function returns an integer greater than, equal to, or
less than 0 if the directory entry name pointed to by d1 is greater than,
equal to, or less than the directory entry name pointed to by d2 when
both are interpreted as appropriate to the current locale. There is no
return value reserved to indicate an error.

ERRORS

The scandir() function will fail if:

EOVERFLOW
The number of directory entries exceeds the number that can
be represented by an int.

USAGE

The scandir() and alphasort() functions have transitional interfaces for
64-bit file offsets. See lf64(7).

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Stable |
+--------------------+-----------------+
|MT-Level | See below. |
+--------------------+-----------------+


The scandir() function is Unsafe. The alphasort() function is Safe.

SEE ALSO

malloc(3C), qsort(3C), readdir(3C), strcoll(3C), attributes(7), lf64(7)

May 4, 2004 SCANDIR(3C)