libgfortran/intrinsics/hostnm.c

   1 /* Implementation of the HOSTNM intrinsic.
   2    Copyright (C) 2005-2020 Free Software Foundation, Inc.
   3    Contributed by François-Xavier Coudert <coudert@clipper.ens.fr>
   4
   5 This file is part of the GNU Fortran runtime library (libgfortran).
   6
   7 Libgfortran is free software; you can redistribute it and/or
   8 modify it under the terms of the GNU General Public
   9 License as published by the Free Software Foundation; either
  10 version 3 of the License, or (at your option) any later version.
  11
  12 Libgfortran is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 Under Section 7 of GPL version 3, you are granted additional
  18 permissions described in the GCC Runtime Library Exception, version
  19 3.1, as published by the Free Software Foundation.
  20
  21 You should have received a copy of the GNU General Public License and
  22 a copy of the GCC Runtime Library Exception along with this program;
  23 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 <http://www.gnu.org/licenses/>.  */
  25
  26 #include "libgfortran.h"
  27
  28 #include <errno.h>
  29 #include <string.h>
  30
  31 #ifdef HAVE_UNISTD_H
  32 #include <unistd.h>
  33 #endif
  34
  35 #include <limits.h>
  36
  37 #ifndef HOST_NAME_MAX
  38 #define HOST_NAME_MAX 255
  39 #endif
  40
  41
  42 /* Windows32 version */
  43 #if defined __MINGW32__ && !defined  HAVE_GETHOSTNAME
  44 #define WIN32_LEAN_AND_MEAN
  45 #include <windows.h>
  46 #include <errno.h>
  47
  48 static int
  49 w32_gethostname (char *name, size_t len)
  50 {
  51   /* We could try the WinSock API gethostname, but that will
  52      fail if WSAStartup function has has not been called.  We don't
  53     really need a name that will be understood by socket API, so avoid
  54     unnecessary dependence on WinSock libraries by using
  55     GetComputerName instead.  */
  56
  57   /* On Win9x GetComputerName fails if the input size is less
  58      than MAX_COMPUTERNAME_LENGTH + 1.  */
  59   char buffer[MAX_COMPUTERNAME_LENGTH + 1];
  60   DWORD size =  sizeof (buffer);
  61
  62   if (!GetComputerName (buffer, &size))
  63     return -1;
  64
  65   if ((size = strlen (buffer) + 1)  > len)
  66     {
  67       errno = EINVAL;
  68       /* Truncate as per POSIX spec.  We do not NUL-terminate. */
  69       size = len;
  70     }
  71   memcpy (name, buffer, (size_t) size);
  72
  73   return 0;
  74 }
  75
  76 #undef gethostname
  77 #define gethostname w32_gethostname
  78 #define  HAVE_GETHOSTNAME 1
  79
  80 #endif
  81
  82
  83 /* SUBROUTINE HOSTNM(NAME, STATUS)
  84    CHARACTER(len=*), INTENT(OUT) :: NAME
  85    INTEGER, INTENT(OUT), OPTIONAL :: STATUS  */
  86
  87 #ifdef HAVE_GETHOSTNAME
  88 static int
  89 hostnm_0 (char *name, gfc_charlen_type name_len)
  90 {
  91   char p[HOST_NAME_MAX + 1];
  92   int val;
  93
  94   memset (name, ' ', name_len);
  95
  96   size_t reqlen = sizeof (p) > (size_t) name_len + 1
  97     ? (size_t) name_len + 1: sizeof (p);
  98   val = gethostname (p, reqlen);
  99
 100   if (val == 0)
 101   {
 102     for (gfc_charlen_type i = 0; i < name_len && p[i] != '\0'; i++)
 103       name[i] = p[i];
 104   }
 105
 106   return ((val == 0) ? 0 : errno);
 107 }
 108
 109 extern void hostnm_i4_sub (char *, GFC_INTEGER_4 *, gfc_charlen_type);
 110 iexport_proto(hostnm_i4_sub);
 111
 112 void
 113 hostnm_i4_sub (char *name, GFC_INTEGER_4 *status, gfc_charlen_type name_len)
 114 {
 115   int val = hostnm_0 (name, name_len);
 116   if (status != NULL)
 117     *status = val;
 118 }
 119 iexport(hostnm_i4_sub);
 120
 121 extern void hostnm_i8_sub (char *, GFC_INTEGER_8 *, gfc_charlen_type);
 122 iexport_proto(hostnm_i8_sub);
 123
 124 void
 125 hostnm_i8_sub (char *name, GFC_INTEGER_8 *status, gfc_charlen_type name_len)
 126 {
 127   int val = hostnm_0 (name, name_len);
 128   if (status != NULL)
 129     *status = val;
 130 }
 131 iexport(hostnm_i8_sub);
 132
 133 extern GFC_INTEGER_4 hostnm (char *, gfc_charlen_type);
 134 export_proto(hostnm);
 135
 136 GFC_INTEGER_4
 137 hostnm (char *name, gfc_charlen_type name_len)
 138 {
 139   return hostnm_0 (name, name_len);
 140 }
 141 #endif