view lib/gethostname.c @ 14641:9a3f3761a941

getcwd: fix mingw bugs On mingw, getcwd(NULL,1) succeeds, even though glibc documents that with a non-zero size, the allocation will not exceed that many bytes. On mingw, getcwd has the wrong signature. However, we don't have to check for this if anything else triggers the replacement. Also, fix a type bug that crept into the original getcwd-lgpl commit. * m4/getcwd.m4 (gl_FUNC_GETCWD_NULL): Detect one mingw bug. * doc/posix-functions/getcwd.texi (getcwd): Document the problems. * lib/getcwd-lgpl.c (rpl_getcwd): Fix return type. Signed-off-by: Eric Blake <eblake@redhat.com>
author Eric Blake <eblake@redhat.com>
date Wed, 27 Apr 2011 20:40:21 -0600
parents 97fc9a21a8fb
children 8250f2777afc
line wrap: on
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/* gethostname emulation for SysV and POSIX.1.

   Copyright (C) 1992, 2003, 2006, 2008-2011 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/* David MacKenzie <djm@gnu.ai.mit.edu>
   Windows port by Simon Josefsson <simon@josefsson.org> */

#include <config.h>

#if !((defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__)
/* Unix API.  */

/* Specification.  */
#include <unistd.h>

#ifdef HAVE_UNAME
# include <sys/utsname.h>
#endif

#include <string.h>

/* Put up to LEN chars of the host name into NAME.
   Null terminate it if the name is shorter than LEN.
   Return 0 if ok, -1 if error.  */

#include <stddef.h>

int
gethostname (char *name, size_t len)
{
#ifdef HAVE_UNAME
  struct utsname uts;

  if (uname (&uts) == -1)
    return -1;
  if (len > sizeof (uts.nodename))
    {
      /* More space than we need is available.  */
      name[sizeof (uts.nodename)] = '\0';
      len = sizeof (uts.nodename);
    }
  strncpy (name, uts.nodename, len);
#else
  strcpy (name, "");            /* Hardcode your system name if you want.  */
#endif
  return 0;
}

#else
/* Native Windows API.  Which primitive to choose?
   - gethostname() requires linking with -lws2_32.
   - GetComputerName() does not return the right kind of hostname.
   - GetComputerNameEx(ComputerNameDnsHostname,...) returns the right hostname,
     but it is hard to use portably:
       - It requires defining _WIN32_WINNT to at least 0x0500.
       - With mingw, it also requires
         "#define GetComputerNameEx GetComputerNameExA".
       - With older versions of mingw, none of the declarations are present at
         all, not even of the enum value ComputerNameDnsHostname.
   So we use gethostname().  Linking with -lws2_32 is the least evil.  */

#define WIN32_LEAN_AND_MEAN
/* Get winsock2.h. */
#include <unistd.h>

/* Get INT_MAX.  */
#include <limits.h>

/* Get set_winsock_errno. */
#include "w32sock.h"

#include "sockets.h"

#undef gethostname

int
rpl_gethostname (char *name, size_t len)
{
  int r;

  if (len > INT_MAX)
    len = INT_MAX;
  gl_sockets_startup (SOCKETS_1_1);
  r = gethostname (name, (int) len);
  if (r < 0)
    set_winsock_errno ();

  return r;
}

#endif