Manpages - opendir.3

Table of Contents

NAME

opendir, fdopendir - open a directory

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 per-process limit on the number of open file descriptors has been reached.
ENFILE
The system-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.

VERSIONS

*fdopendir*() is available in glibc since version 2.4.

ATTRIBUTES

For an explanation of the terms used in this section, see *attributes*(7).

Interface Attribute Value
*opendir*(), *fdopendir*() Thread safety MT-Safe

CONFORMING TO

*opendir*() is present on SVr4, 4.3BSD, and specified in POSIX.1-2001. *fdopendir*() is specified in POSIX.1-2008.

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 close-on-exec flag for the file descriptor underlying the DIR *. The *fdopendir*() function leaves the setting of the close-on-exec flag unchanged for the file descriptor, fd. POSIX.1-200x leaves it unspecified whether a successful call to *fdopendir*() will set the close-on-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)

COLOPHON

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Author: dt

Created: 2022-02-20 Sun 18:06