libgfortran/intrinsics/env.c

   1 /* Implementation of the GETENV g77, and
   2    GET_ENVIRONMENT_VARIABLE F2003, intrinsics.
   3    Copyright (C) 2004-2017 Free Software Foundation, Inc.
   4    Contributed by Janne Blomqvist.
   5
   6 This file is part of the GNU Fortran 95 runtime library (libgfortran).
   7
   8 Libgfortran is free software; you can redistribute it and/or
   9 modify it under the terms of the GNU General Public
  10 License as published by the Free Software Foundation; either
  11 version 3 of the License, or (at your option) any later version.
  12
  13 Libgfortran is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 Under Section 7 of GPL version 3, you are granted additional
  19 permissions described in the GCC Runtime Library Exception, version
  20 3.1, as published by the Free Software Foundation.
  21
  22 You should have received a copy of the GNU General Public License and
  23 a copy of the GCC Runtime Library Exception along with this program;
  24 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  25 <http://www.gnu.org/licenses/>.  */
  26
  27 #include "libgfortran.h"
  28 #include <string.h>
  29
  30
  31 /* GETENV (NAME, VALUE), g77 intrinsic for retrieving the value of
  32    an environment variable. The name of the variable is specified in
  33    NAME, and the result is stored into VALUE.  */
  34
  35 void PREFIX(getenv) (char *, char *, gfc_charlen_type, gfc_charlen_type);
  36 export_proto_np(PREFIX(getenv));
  37
  38 void
  39 PREFIX(getenv) (char * name, char * value, gfc_charlen_type name_len,
  40                 gfc_charlen_type value_len)
  41 {
  42   char *name_nt;
  43   char *res = NULL;
  44
  45   if (name == NULL || value == NULL)
  46     runtime_error ("Both arguments to getenv are mandatory.");
  47
  48   if (value_len < 1 || name_len < 1)
  49     runtime_error ("Zero length string(s) passed to getenv.");
  50   else
  51     memset (value, ' ', value_len); /* Blank the string.  */
  52
  53   /* Make a null terminated copy of the string.  */
  54   name_nt = fc_strdup (name, name_len);
  55
  56   res = getenv(name_nt);
  57
  58   free (name_nt);
  59
  60   /* If res is NULL, it means that the environment variable didn't
  61      exist, so just return.  */
  62   if (res == NULL)
  63     return;
  64
  65   cf_strcpy (value, value_len, res);
  66 }
  67
  68
  69 /* GET_ENVIRONMENT_VARIABLE (name, [value, length, status, trim_name])
  70    is a F2003 intrinsic for getting an environment variable.  */
  71
  72 /* Status codes specifyed by the standard. */
  73 #define GFC_SUCCESS 0
  74 #define GFC_VALUE_TOO_SHORT -1
  75 #define GFC_NAME_DOES_NOT_EXIST 1
  76
  77 /* This is also specified by the standard and means that the
  78    processor doesn't support environment variables.  At the moment,
  79    gfortran doesn't use it.  */
  80 #define GFC_NOT_SUPPORTED 2
  81
  82 /* Processor-specific failure code.  */
  83 #define GFC_FAILURE 42
  84
  85 extern void get_environment_variable_i4 (char *, char *, GFC_INTEGER_4 *,
  86                                          GFC_INTEGER_4 *, GFC_LOGICAL_4 *,
  87                                          gfc_charlen_type, gfc_charlen_type);
  88 iexport_proto(get_environment_variable_i4);
  89
  90 void
  91 get_environment_variable_i4 (char *name, char *value, GFC_INTEGER_4 *length,
  92                              GFC_INTEGER_4 *status, GFC_LOGICAL_4 *trim_name,
  93                              gfc_charlen_type name_len,
  94                              gfc_charlen_type value_len)
  95 {
  96   int stat = GFC_SUCCESS, res_len = 0;
  97   char *name_nt;
  98   char *res;
  99
 100   if (name == NULL)
 101     runtime_error ("Name is required for get_environment_variable.");
 102
 103   if (value == NULL && length == NULL && status == NULL && trim_name == NULL)
 104     return;
 105
 106   if (name_len < 1)
 107     runtime_error ("Zero-length string passed as name to "
 108                    "get_environment_variable.");
 109
 110   if (value != NULL)
 111     {
 112       if (value_len < 1)
 113         runtime_error ("Zero-length string passed as value to "
 114                        "get_environment_variable.");
 115       else
 116         memset (value, ' ', value_len); /* Blank the string.  */
 117     }
 118
 119   if ((!trim_name) || *trim_name)
 120     name_nt = fc_strdup (name, name_len);
 121   else
 122     name_nt = fc_strdup_notrim (name, name_len);
 123
 124   res = getenv(name_nt);
 125
 126   free (name_nt);
 127
 128   if (res == NULL)
 129     stat = GFC_NAME_DOES_NOT_EXIST;
 130   else
 131     {
 132       res_len = strlen(res);
 133       if (value != NULL)
 134         {
 135           if (value_len < res_len)
 136             {
 137               memcpy (value, res, value_len);
 138               stat = GFC_VALUE_TOO_SHORT;
 139             }
 140           else
 141             memcpy (value, res, res_len);
 142         }
 143     }
 144
 145   if (status != NULL)
 146     *status = stat;
 147
 148   if (length != NULL)
 149     *length = res_len;
 150 }
 151 iexport(get_environment_variable_i4);
 152
 153
 154 /* INTEGER*8 wrapper for get_environment_variable.  */
 155
 156 extern void get_environment_variable_i8 (char *, char *, GFC_INTEGER_8 *,
 157                                          GFC_INTEGER_8 *, GFC_LOGICAL_8 *,
 158                                          gfc_charlen_type, gfc_charlen_type);
 159 export_proto(get_environment_variable_i8);
 160
 161 void
 162 get_environment_variable_i8 (char *name, char *value, GFC_INTEGER_8 *length,
 163                              GFC_INTEGER_8 *status, GFC_LOGICAL_8 *trim_name,
 164                              gfc_charlen_type name_len,
 165                              gfc_charlen_type value_len)
 166 {
 167   GFC_INTEGER_4 length4, status4;
 168   GFC_LOGICAL_4 trim_name4;
 169
 170   if (trim_name)
 171     trim_name4 = *trim_name;
 172
 173   get_environment_variable_i4 (name, value, &length4, &status4,
 174                                trim_name ? &trim_name4 : NULL,
 175                                name_len, value_len);
 176
 177   if (length)
 178     *length = length4;
 179
 180   if (status)
 181     *status = status4;
 182 }