Re: declare sethostname if unistd.h doesn't

[Simon Josefsson]

Ben Walton <address@hidden> writes:

> Hi All,
>
> When testing the pending release of inetutils on solaris 9/10, I
> discovered that sethostname isn't declared in unistd.h on Solaris.
> The following patch adds handling for this although I'm not positive
> that it's the best way to do it.  At the very least it's a starting
> point for discussing the best way to add the required support.
>
> Based on the 'not corrected by' section in
> glibc-functions/sethostname.texi, I was tempted to make this a
> separate module but decided not to go that far yet.  If that's the
> better or more proper solution, I don't mind resubmitting.
>
> Comments and criticisms are welcomed.

Have you tested that it resolves the portability issue?  If so that is
great.  My man page says Solaris uses this prototype:

     int sethostname(char *name, int namelen);

however possibly int and size_t have the same size on all Solaris 8 and
9 architectures?

In any case, I support installing this if it does something useful on at
least some (Solaris) machine, since the current situation does not
appear to work on any (Solaris) machine.

/Simon

> Thanks
> -Ben
>
> From 0dd943363bbd4d2884b8851ccbd703fee5eb6353 Mon Sep 17 00:00:00 2001
> From: Ben Walton <address@hidden>
> Date: Sat, 19 Nov 2011 23:13:08 +0100
> Subject: [PATCH] unistd: declare sethostname when required
>
> * m4/unistd_h.m4 (gl_UNISTD_H): Check for missing sethostname
>   declaration
> * lib/unistd.in.h: Define sethostname if the function is available but
>   the prototype isn't.
>
> Signed-off-by: Ben Walton <address@hidden>
> ---
>  ChangeLog                            |    8 ++++++++
>  doc/glibc-functions/sethostname.texi |    2 ++
>  lib/unistd.in.h                      |    4 ++++
>  m4/unistd_h.m4                       |    6 ++++++
>  4 files changed, 20 insertions(+), 0 deletions(-)
>
> diff --git a/ChangeLog b/ChangeLog
> index 8725c92..aeaeb00 100644
> --- a/ChangeLog
> +++ b/ChangeLog
> @@ -1,3 +1,11 @@
> +2011-11-19  Ben Walton   <address@hidden>
> +
> +     unistd: declare sethostname when required
> +     * m4/unistd_h.m4 (gl_UNISTD_H): Check for missing sethostname
> +     declaration
> +     * lib/unistd.in.h: Define sethostname if the function is
> +     available but the prototype isn't.
> +
>  2011-11-19  Bruno Haible  <address@hidden>
>  
>       Depend on module fcntl-h when AT_FDCWD is used.
> diff --git a/doc/glibc-functions/sethostname.texi 
> b/doc/glibc-functions/sethostname.texi
> index 64c4548..88d2ed8 100644
> --- a/doc/glibc-functions/sethostname.texi
> +++ b/doc/glibc-functions/sethostname.texi
> @@ -6,6 +6,8 @@ Gnulib module: ---
>  
>  Portability problems fixed by Gnulib:
>  @itemize
> +Some platforms provide the function but not the prototype:
> +Solaris 9 and 10.
>  @end itemize
>  
>  Portability problems not fixed by Gnulib:
> diff --git a/lib/unistd.in.h b/lib/unistd.in.h
> index f53f34b..057eaab 100644
> --- a/lib/unistd.in.h
> +++ b/lib/unistd.in.h
> @@ -683,6 +683,10 @@ _GL_WARN_ON_USE (getgroups, "getgroups is unportable - "
>  # endif
>  #endif
>  
> +#if HAVE_SETHOSTNAME && !HAVE_DECL_SETHOSTNAME
> +_GL_FUNCDECL_SYS (sethostname, int, (const char *name, size_t len)
> +               _GL_ARG_NONNULL ((1)));
> +#endif
>  
>  #if @GNULIB_GETHOSTNAME@
>  /* Return the standard host name of the machine.
> diff --git a/m4/unistd_h.m4 b/m4/unistd_h.m4
> index 57c8094..8b5cf6f 100644
> --- a/m4/unistd_h.m4
> +++ b/m4/unistd_h.m4
> @@ -21,6 +21,12 @@ AC_DEFUN([gl_UNISTD_H],
>    fi
>    AC_SUBST([HAVE_UNISTD_H])
>  
> +  dnl Ensure there is a prototype for sethostname
> +  AC_CHECK_DECLS([sethostname])
> +  dnl Detect the function too as we don't need the prototype if the function
> +  dnl isn't available.
> +  AC_CHECK_FUNCS([sethostname])
> +
>    dnl Ensure the type pid_t gets defined.
>    AC_REQUIRE([AC_TYPE_PID_T])