SCANDIR(3C) Standard C Library Functions SCANDIR(3C)
scandir, alphasort - scan a directory
#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);
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.
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.
The scandir() function will fail if:
EOVERFLOW
The number of directory entries exceeds the number that
can be represented by an int.
The scandir() and alphasort() functions have transitional interfaces
for 64-bit file offsets. See lf64(7).
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.
malloc(3C), qsort(3C), readdir(3C), strcoll(3C), attributes(7),
lf64(7)
May 4, 2004 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)