@node dirent.h
@section @file{dirent.h}

POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/dirent.h.html}

Gnulib module: dirent
@mindex dirent

Portability problems fixed by Gnulib:
@itemize
@item
This header file is missing on some platforms:
MSVC 14.

@item
Although many systems define directory entry type macros like @code{DT_DIR},
some do not:
Minix 3.1.8, AIX 7.2, HP-UX 11, Solaris 11.4, mingw.

@item
The directory entry type macro @code{DT_WHT} is missing on many systems:
All systems where @code{DT_DIR} is missing, plus OpenBSD 7.5.

@item
The conversion macros @code{DTTOIF} and @code{IFTODT} are missing on
many systems (however, the Gnulib replacement macros
may evaluate their arguments multiple times):
All systems where @code{DT_DIR} is missing, plus OpenBSD 7.5.

@item
The type @code{ino_t} is missing on some platforms:
glibc 2.23 and others.

@end itemize

Portability problems not fixed by Gnulib:
@itemize
@item
Although many systems define a @code{struct dirent} member named
@code{d_type}, some do not:
Minix 3.1.8, AIX 7.2, HP-UX 11, Solaris 11.4, mingw.

@item
On systems with @code{d_type}, not every filesystem supports
@code{d_type}, and those lacking support will set it to @code{DT_UNKNOWN}.

@item
The POSIX.1-2024 directory entry type macros @code{DT_MQ},
@code{DT_SEM}, @code{DT_SHM} and @code{DT_TMO} are missing on many
platforms.

@item
Some systems define a @code{struct dirent} member named @code{d_namlen}
containing the string length of @code{d_name}, but others do not:
glibc 2.23 on Linux, Minix 3.1.8, Solaris 11.4, Cygwin.
All of these, except Cygwin, have a member @code{d_reclen} instead,
that has a different semantics.

@item
Some systems define a @code{struct dirent} member named @code{d_off}
containing a magic cookie suitable as an argument to @code{seekdir},
but others do not:
glibc 2.23 on Hurd, macOS 11.1, FreeBSD 11.0, NetBSD 10.0, OpenBSD 7.5, AIX 5.1, HP-UX 11, Cygwin, mingw.

@item
Some systems define a @code{struct dirent} member named
@code{d_reclen} containing the number of bytes in the directory entry
record, but others do not.  This member has limited utility, as it is
an implementation detail.
@end itemize
