1  /* Implementation of the GETLOG g77 intrinsic.
       2     Copyright (C) 2005-2023 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  }