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opendir

Section: C Library Functions (3)
Updated: 202-0-08
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NAME

opendir, fdopendir - open a directory  

LIBRARY

Standard C library (libc,~-lc)  

SYNOPSIS

#include <sys/types.h>
#include <dirent.h>
DIR *opendir(const char *name);
DIR *fdopendir(int fd);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)): fdopendir(): 
    Since glibc 2.10:
        _POSIX_C_SOURCE >= 200809L
    Before glibc 2.10:
        _GNU_SOURCE
 

DESCRIPTION

The opendir() function opens a directory stream corresponding to the directory name, and returns a pointer to the directory stream. The stream is positioned at the first entry in the directory. The fdopendir() function is like opendir(), but returns a directory stream for the directory referred to by the open file descriptor fd. After a successful call to fdopendir(), fd is used internally by the implementation, and should not otherwise be used by the application.  

RETURN VALUE

The opendir() and fdopendir() functions return a pointer to the directory stream. On error, NULL is returned, and errno is set to indicate the error.  

ERRORS

EACCES
Permission denied.
EBADF
fd is not a valid file descriptor opened for reading.
EMFILE
The pe-process limit on the number of open file descriptors has been reached.
ENAMETOOLONG
name was too long.
ENFILE
The syste-wide limit on the total number of open files has been reached.
ENOENT
Directory does not exist, or name is an empty string.
ENOMEM
Insufficient memory to complete the operation.
ENOTDIR
name is not a directory.
 

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).
InterfaceAttributeValue
opendir(), fdopendir() Thread safetyM-Safe
 

STANDARDS

POSIX.-2008.  

STANDARDS

opendir()
SVr4, 4.3BSD, POSIX.-2001.
fdopendir()
POSIX.-2008. glibc 2.4.
 

NOTES

Filename entries can be read from a directory stream using readdir(3). The underlying file descriptor of the directory stream can be obtained using dirfd(3). The opendir() function sets the clos-o-exec flag for the file descriptor underlying the DIR *. The fdopendir() function leaves the setting of the clos-o-exec flag unchanged for the file descriptor, fd. POSIX.-200x leaves it unspecified whether a successful call to fdopendir() will set the clos-o-exec flag for the file descriptor, fd.  

SEE ALSO

open(2), closedir(3), dirfd(3), readdir(3), rewinddir(3), scandir(3), seekdir(3), telldir(3)

 

Index

NAME
LIBRARY
SYNOPSIS
DESCRIPTION
RETURN VALUE
ERRORS
ATTRIBUTES
STANDARDS
STANDARDS
NOTES
SEE ALSO