Re: O_CLOEXEC support (was: popen bugs, popen_safer)

[Bruno Haible]

Eric Blake wrote:
> we also need to
> tweak the O_NOINHERIT flag of an existing fd without having to use dup in
> cloexec.c (I'm hoping the windows functions GetHandleInformation and
> SetHandleInformation work here).

I don't see how to make it work without a lot of dup() calls and without
assuming that O_APPEND is not being used.

> pipe2, dup3, accept4, mkostemp - GNU/Linux extensions - New modules to
> match recent glibc extensions around the recently added syscalls on Linux
> for passing O_CLOEXEC (or O_NONBLOCK) via the flag argument.

With these functions, we can work around the impossibility of fcntl F_SETFD
on mingw.

As a starter, let me add some dummy documentation about these functions.


2009-08-22  Bruno Haible  <address@hidden>

        Reference some new glibc functions.
        * doc/glibc-functions/accept4.texi: New file.
        * doc/glibc-functions/dup3.texi: New file.
        * doc/glibc-functions/mkostemp.texi: New file.
        * doc/glibc-functions/pipe2.texi: New file.
        * doc/gnulib.texi (Glibc stdlib.h): Refer to mkostemp.
        (Glibc sys/socket.h): Refer to accept4.
        (Glibc unistd.h): Refer to dup3, pipe2.
        Reported by Eric Blake.

Changing permissions from . to 100644
--- doc/glibc-functions/accept4.texi.orig       2008-06-06 22:36:48.000000000 
+0200
+++ doc/glibc-functions/accept4.texi    2009-08-22 15:18:45.000000000 +0200
@@ -0,0 +1,16 @@
address@hidden accept4
address@hidden @code{accept4}
address@hidden accept4
+
+Gnulib module: ---
+
+Portability problems fixed by Gnulib:
address@hidden
address@hidden itemize
+
+Portability problems not fixed by Gnulib:
address@hidden
address@hidden
+This function is missing on all non-glibc platforms:
+MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, AIX 5.1, HP-UX 11, IRIX 
6.5, OSF/1 5.1, Solaris 10, Cygwin, mingw, Interix 3.5, BeOS.
address@hidden itemize
Changing permissions from . to 100644
--- doc/glibc-functions/dup3.texi.orig  2008-06-06 22:36:48.000000000 +0200
+++ doc/glibc-functions/dup3.texi       2009-08-22 14:53:56.000000000 +0200
@@ -0,0 +1,16 @@
address@hidden dup3
address@hidden @code{dup3}
address@hidden dup3
+
+Gnulib module: ---
+
+Portability problems fixed by Gnulib:
address@hidden
address@hidden itemize
+
+Portability problems not fixed by Gnulib:
address@hidden
address@hidden
+This function is missing on all non-glibc platforms:
+MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, AIX 5.1, HP-UX 11, IRIX 
6.5, OSF/1 5.1, Solaris 10, Cygwin, mingw, Interix 3.5, BeOS.
address@hidden itemize
Changing permissions from . to 100644
--- doc/glibc-functions/mkostemp.texi.orig      2008-06-06 22:36:48.000000000 
+0200
+++ doc/glibc-functions/mkostemp.texi   2009-08-22 15:18:56.000000000 +0200
@@ -0,0 +1,16 @@
address@hidden mkostemp
address@hidden @code{mkostemp}
address@hidden mkostemp
+
+Gnulib module: ---
+
+Portability problems fixed by Gnulib:
address@hidden
address@hidden itemize
+
+Portability problems not fixed by Gnulib:
address@hidden
address@hidden
+This function is missing on all non-glibc platforms:
+MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, AIX 5.1, HP-UX 11, IRIX 
6.5, OSF/1 5.1, Solaris 10, Cygwin, mingw, Interix 3.5, BeOS.
address@hidden itemize
Changing permissions from . to 100644
--- doc/glibc-functions/pipe2.texi.orig 2008-06-06 22:36:48.000000000 +0200
+++ doc/glibc-functions/pipe2.texi      2009-08-22 14:54:04.000000000 +0200
@@ -0,0 +1,16 @@
address@hidden pipe2
address@hidden @code{pipe2}
address@hidden pipe2
+
+Gnulib module: ---
+
+Portability problems fixed by Gnulib:
address@hidden
address@hidden itemize
+
+Portability problems not fixed by Gnulib:
address@hidden
address@hidden
+This function is missing on all non-glibc platforms:
+MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, AIX 5.1, HP-UX 11, IRIX 
6.5, OSF/1 5.1, Solaris 10, Cygwin, mingw, Interix 3.5, BeOS.
address@hidden itemize
--- doc/gnulib.texi.orig        2009-08-22 15:24:43.000000000 +0200
+++ doc/gnulib.texi     2009-08-22 15:20:28.000000000 +0200
@@ -5063,6 +5063,7 @@
 * jrand48_r::
 * lcong48_r::
 * lrand48_r::
+* mkostemp::
 * mrand48_r::
 * nrand48_r::
 * on_exit::
@@ -5103,6 +5104,7 @@
 @include glibc-functions/jrand48_r.texi
 @include glibc-functions/lcong48_r.texi
 @include glibc-functions/lrand48_r.texi
address@hidden glibc-functions/mkostemp.texi
 @include glibc-functions/mrand48_r.texi
 @include glibc-functions/nrand48_r.texi
 @include glibc-functions/on_exit.texi
@@ -5370,9 +5372,11 @@
 @section Glibc Extensions to @code{<sys/socket.h>}
 
 @menu
+* accept4::
 * isfdtype::
 @end menu
 
address@hidden glibc-functions/accept4.texi
 @include glibc-functions/isfdtype.texi
 
 @node Glibc sys/stat.h
@@ -5655,6 +5659,7 @@
 * brk::
 * chroot::
 * daemon::
+* dup3::
 * endusershell::
 * euidaccess::
 * get_current_dir_name::
@@ -5666,6 +5671,7 @@
 * getresuid::
 * getusershell::
 * group_member::
+* pipe2::
 * profil::
 * revoke::
 * sbrk::
@@ -5685,6 +5691,7 @@
 @include glibc-functions/brk.texi
 @include glibc-functions/chroot.texi
 @include glibc-functions/daemon.texi
address@hidden glibc-functions/dup3.texi
 @include glibc-functions/endusershell.texi
 @include glibc-functions/euidaccess.texi
 @include glibc-functions/get_current_dir_name.texi
@@ -5696,6 +5703,7 @@
 @include glibc-functions/getresuid.texi
 @include glibc-functions/getusershell.texi
 @include glibc-functions/group_member.texi
address@hidden glibc-functions/pipe2.texi
 @include glibc-functions/profil.texi
 @include glibc-functions/revoke.texi
 @include glibc-functions/sbrk.texi