PROLOG

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of this interface
       may differ (consult the corresponding Linux manual page for details of Linux behavior), or the  interface
       may not be implemented on Linux.

NAME

       dirent.h — format of directory entries

SYNOPSIS

       #include <dirent.h>

DESCRIPTION

       The internal format of directories is unspecified.

       The <dirent.h> header shall define the following type:

       DIR     A type representing a directory stream. The DIR type may be an incomplete type.

       It shall also define the structure dirent which shall include the following members:

           ino_t  d_ino       File serial number.
           char   d_name[]    Filename string of entry.

       The <dirent.h> header shall define the ino_t type as described in <sys/types.h>.

       The  array  d_name  is  of  unspecified  size,  but  shall contain a filename of at most {NAME_MAX} bytes
       followed by a terminating null byte.

       The following shall be declared as functions and may also be defined as macros. Function prototypes shall
       be provided.

           int            alphasort(const struct dirent **, const struct dirent **);
           int            closedir(DIR *);
           int            dirfd(DIR *);
           DIR           *fdopendir(int);
           DIR           *opendir(const char *);
           struct dirent *readdir(DIR *);
           int            readdir_r(DIR *restrict, struct dirent *restrict,
                              struct dirent **restrict);
           void           rewinddir(DIR *);
           int            scandir(const char *, struct dirent ***,
                              int (*)(const struct dirent *),
                              int (*)(const struct dirent **,
                              const struct dirent **));
           void           seekdir(DIR *, long);
           long           telldir(DIR *);

       The following sections are informative.

APPLICATION USAGE

       None.

RATIONALE

       Information similar to that in the <dirent.h> header is contained in a file <sys/dir.h> in  4.2  BSD  and
       4.3  BSD.  The  equivalent  in these implementations of struct dirent from this volume of POSIX.1‐2017 is
       struct direct.  The filename  was  changed  because  the  name  <sys/dir.h>  was  also  used  in  earlier
       implementations to refer to definitions related to the older access method; this produced name conflicts.
       The name of the structure was changed because this volume of POSIX.1‐2017 does not completely define what
       is in the structure, so it could be different on some implementations from struct direct.

       The name of an array of char of an unspecified size should not be used as an lvalue. Use of:

           sizeof(d_name)

       is incorrect; use:

           strlen(d_name)

       instead.

       The  array  of char d_name is not a fixed size. Implementations may need to declare struct dirent with an
       array size for d_name of 1, but the actual number of bytes provided matches (or  only  slightly  exceeds)
       the length of the filename string.

FUTURE DIRECTIONS

       None.

SEE ALSO

       <sys_types.h>

       The  System  Interfaces volume of POSIX.1‐2017, alphasort(), closedir(), dirfd(), fdopendir(), readdir(),
       rewinddir(), seekdir(), telldir()

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group  Base
       Specifications  Issue  7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics
       Engineers, Inc and The Open Group.  In the event of any discrepancy between this version and the original
       IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee  document.
       The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

       Any  typographical  or formatting errors that appear in this page are most likely to have been introduced
       during  the  conversion  of  the  source  files  to  man  page  format.  To  report  such   errors,   see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                                   2017                                      dirent.h(7POSIX)