libgfortran/intrinsics/getlog.c

   1 /* Implementation of the GETLOG g77 intrinsic.
   2    Copyright (C) 2005-2019 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 <string.h>
  29
  30 #ifdef HAVE_UNISTD_H
  31 #  if defined __MINGW32__ && defined  HAVE_GETLOGIN
  32 #    define _POSIX 1
  33 #  endif
  34 #include <unistd.h>
  35 #endif
  36 #ifdef HAVE_PWD_H
  37 #include <pwd.h>
  38 #endif
  39
  40 /* Windows32 version */
  41 #if defined __MINGW32__ && !defined  HAVE_GETLOGIN
  42 #define WIN32_LEAN_AND_MEAN
  43 #include <windows.h>
  44 #include <lmcons.h>  /* for UNLEN */
  45
  46 static char *
  47 w32_getlogin (void)
  48 {
  49   static char name [UNLEN + 1];
  50   DWORD namelen = sizeof (name);
  51
  52   GetUserName (name, &namelen);
  53   return (name[0] == 0 ?  NULL : name);
  54 }
  55
  56 #undef getlogin
  57 #define getlogin w32_getlogin
  58 #define HAVE_GETLOGIN 1
  59
  60 #endif
  61
  62
  63 /* GETLOG (LOGIN), g77 intrinsic for retrieving the login name for the
  64    process.
  65    CHARACTER(len=*), INTENT(OUT) :: LOGIN  */
  66
  67 void PREFIX(getlog) (char *, gfc_charlen_type);
  68 export_proto_np(PREFIX(getlog));
  69
  70 void
  71 PREFIX(getlog) (char * login, gfc_charlen_type login_len)
  72 {
  73   char *p;
  74
  75   memset (login, ' ', login_len); /* Blank the string.  */
  76
  77 #if defined(HAVE_POSIX_GETPWUID_R) && defined(HAVE_GETEUID)
  78   struct passwd pwd;
  79   struct passwd *result;
  80   char *buf;
  81   int err;
  82   /* To be pedantic, buflen should be determined by
  83      sysconf(_SC_GETPW_R_SIZE_MAX), which is 1024 on some tested
  84      targets; we do something simple in case the target doesn't
  85      support sysconf.  */
  86   static const size_t buflen = 1024;
  87   buf = xmalloc (buflen);
  88   err = getpwuid_r (geteuid (), &pwd, buf, buflen, &result);
  89   if (err != 0 || result == NULL)
  90     goto cleanup;
  91   p = pwd.pw_name;
  92 #elif defined(HAVE_GETPWUID) && defined(HAVE_GETEUID)
  93   {
  94     struct passwd *pw = getpwuid (geteuid ());
  95     if (pw)
  96       p = pw->pw_name;
  97     else
  98       return;
  99   }
 100 #elif HAVE_GETLOGIN
 101   p = getlogin();
 102 # else
 103   return;
 104 #endif
 105
 106   if (p == NULL)
 107     goto cleanup;
 108
 109   gfc_charlen_type p_len = strlen (p);
 110   if (login_len < p_len)
 111     p_len = login_len;
 112   memcpy (login, p, p_len);
 113
 114  cleanup:
 115 #if defined (HAVE_POSIX_GETPWUID_R) && defined(HAVE_GETEUID)
 116   free (buf);
 117 #else
 118   ;
 119 #endif
 120 }