libgfortran/intrinsics/getlog.c

   1 /* Implementation of the GETLOG g77 intrinsic.
   2    Copyright (C) 2005-2016 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 <stdlib.h>
  29 #include <string.h>
  30
  31 #ifdef HAVE_UNISTD_H
  32 #  if defined __MINGW32__ && defined  HAVE_GETLOGIN
  33 #    define _POSIX 1
  34 #  endif
  35 #include <unistd.h>
  36 #endif
  37 #ifdef HAVE_PWD_H
  38 #include <pwd.h>
  39 #endif
  40
  41 /* Windows32 version */
  42 #if defined __MINGW32__ && !defined  HAVE_GETLOGIN
  43 #define WIN32_LEAN_AND_MEAN
  44 #include <windows.h>
  45 #include <lmcons.h>  /* for UNLEN */
  46
  47 static char *
  48 w32_getlogin (void)
  49 {
  50   static char name [UNLEN + 1];
  51   DWORD namelen = sizeof (name);
  52
  53   GetUserName (name, &namelen);
  54   return (name[0] == 0 ?  NULL : name);
  55 }
  56
  57 #undef getlogin
  58 #define getlogin w32_getlogin
  59 #define HAVE_GETLOGIN 1
  60
  61 #endif
  62
  63
  64 /* GETLOG (LOGIN), g77 intrinsic for retrieving the login name for the
  65    process.
  66    CHARACTER(len=*), INTENT(OUT) :: LOGIN  */
  67
  68 void PREFIX(getlog) (char *, gfc_charlen_type);
  69 export_proto_np(PREFIX(getlog));
  70
  71 void
  72 PREFIX(getlog) (char * login, gfc_charlen_type login_len)
  73 {
  74   int p_len;
  75   char *p;
  76
  77   memset (login, ' ', login_len); /* Blank the string.  */
  78
  79 #if defined(HAVE_POSIX_GETPWUID_R) && defined(HAVE_GETEUID)
  80   struct passwd pwd;
  81   struct passwd *result;
  82   char *buf;
  83   int err;
  84   /* To be pedantic, buflen should be determined by
  85      sysconf(_SC_GETPW_R_SIZE_MAX), which is 1024 on some tested
  86      targets; we do something simple in case the target doesn't
  87      support sysconf.  */
  88   static const size_t buflen = 1024;
  89   buf = xmalloc (buflen);
  90   err = getpwuid_r (geteuid (), &pwd, buf, buflen, &result);
  91   if (err != 0 || result == NULL)
  92     goto cleanup;
  93   p = pwd.pw_name;
  94 #elif defined(HAVE_GETPWUID) && defined(HAVE_GETEUID)
  95   {
  96     struct passwd *pw = getpwuid (geteuid ());
  97     if (pw)
  98       p = pw->pw_name;
  99     else
 100       return;
 101   }
 102 #elif HAVE_GETLOGIN
 103   p = getlogin();
 104 # else
 105   return;
 106 #endif
 107
 108   if (p == NULL)
 109     goto cleanup;
 110
 111   p_len = strlen (p);
 112   if (login_len < p_len)
 113     p_len = login_len;
 114   memcpy (login, p, p_len);
 115
 116  cleanup:
 117 #if defined (HAVE_POSIX_GETPWUID_R) && defined(HAVE_GETEUID)
 118   free (buf);
 119 #else
 120   ;
 121 #endif
 122 }