OPENDIR(3) Library Functions Manual OPENDIR(3)

NAME

opendir — open a directory

SYNOPSIS

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

DIR *opendir(const char *dirname);

DESCRIPTION

The opendir() function opens a directory stream corresponding to the directory named by the dirname argument. The directory stream is positioned at the first entry. If the type DIR , is implemented using a file descriptor, applications will only be able to open up to a total of {OPEN_MAX} files and directories. A successful call to any of the exec functions will close any directory streams that are open in the calling process.

RETURN VALUE

Upon successful completion, opendir() returns a pointer to an object of type DIR . Otherwise, a null pointer is returned and errno is set to indicate the error.

ERRORS

The opendir() function will fail if:

[EACCES]: Search permission is denied for the component of the path prefix of dirname or read permission is denied for dirname.
[ELOOP]: Too many symbolic links were encountered in resolving path .
[ENAMETOOLONG]: The length of the dirname argument exceeds {PATH_MAX}, or a pathname component is longer than {NAME_MAX}.
[ENOENT]: A component of dirname does not name an existing directory or dirname is an empty string.
[ENOTDIR]: A component of dirname is not a directory.

The opendir() function may fail if:

[EMFILE]: {OPEN_MAX} file descriptors are currently open in the calling process.
[ENAMETOOLONG]: Pathname resolution of a symbolic link produced an intermediate result whose length exceeds {PATH_MAX}.
[ENFILE]: Too many files are currently open in the system.

EXAMPLES

None.

APPLICATION USAGE

The opendir() function should be used in conjunction with readdir(3) , closedir(3) and rewinddir(3) to examine the contents of the directory (see the EXAMPLES section in readdir(3) ). This method is recommended for portability.

FUTURE DIRECTIONS

None.