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 .