libgfortran/intrinsics/env.c

   1 /* Implementation of the GETENV g77, and
   2    GET_ENVIRONMENT_VARIABLE F2003, intrinsics.
   3    Copyright (C) 2004 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 2 of the License, or (at your option) any later version.
  12
  13 In addition to the permissions in the GNU General Public License, the
  14 Free Software Foundation gives you unlimited permission to link the
  15 compiled version of this file into combinations with other programs,
  16 and to distribute those combinations without any restriction coming
  17 from the use of this file.  (The General Public License restrictions
  18 do apply in other respects; for example, they cover modification of
  19 the file, and distribution when not linked into a combine
  20 executable.)
  21
  22 Libgfortran is distributed in the hope that it will be useful,
  23 but WITHOUT ANY WARRANTY; without even the implied warranty of
  24 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25 GNU General Public License for more details.
  26
  27 You should have received a copy of the GNU General Public
  28 License along with libgfortran; see the file COPYING.  If not,
  29 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  30 Boston, MA 02111-1307, USA.  */
  31
  32 #include "config.h"
  33 #include <sys/types.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36 #include "libgfortran.h"
  37
  38
  39 /* GETENV (NAME, VALUE), g77 intrinsic for retrieving the value of
  40    an environment variable. The name of the variable is specified in
  41    NAME, and the result is stored into VALUE.  */
  42
  43 void PREFIX(getenv) (char *, char *, gfc_charlen_type, gfc_charlen_type);
  44 export_proto_np(PREFIX(getenv));
  45
  46 void
  47 PREFIX(getenv) (char * name, char * value, gfc_charlen_type name_len,
  48                 gfc_charlen_type value_len)
  49 {
  50   char *name_nt;
  51   char *res = NULL;
  52   int res_len;
  53
  54   if (name == NULL || value == NULL)
  55     runtime_error ("Both arguments to getenv are mandatory.");
  56
  57   if (value_len < 1 || name_len < 1)
  58     runtime_error ("Zero length string(s) passed to getenv.");
  59   else
  60     memset (value, ' ', value_len); /* Blank the string.  */
  61
  62   /* Trim trailing spaces from name.  */
  63   while (name_len > 0 && name[name_len - 1] == ' ')
  64     name_len--;
  65
  66   /* Make a null terminated copy of the string.  */
  67   name_nt = gfc_alloca (name_len + 1);
  68   memcpy (name_nt, name, name_len);
  69   name_nt[name_len] = '\0';
  70
  71   res = getenv(name_nt);
  72
  73   /* If res is NULL, it means that the environment variable didn't
  74      exist, so just return.  */
  75   if (res == NULL)
  76     return;
  77
  78   res_len = strlen(res);
  79   if (value_len < res_len)
  80     memcpy (value, res, value_len);
  81   else
  82     memcpy (value, res, res_len);
  83 }
  84
  85
  86 /* GET_ENVIRONMENT_VARIABLE (name, [value, length, status, trim_name])
  87    is a F2003 intrinsic for getting an environment variable.  */
  88
  89 /* Status codes specifyed by the standard. */
  90 #define GFC_SUCCESS 0
  91 #define GFC_VALUE_TOO_SHORT -1
  92 #define GFC_NAME_DOES_NOT_EXIST 1
  93
  94 /* This is also specified by the standard and means that the
  95    processor doesn't support environment variables.  At the moment,
  96    gfortran doesn't use it.  */
  97 #define GFC_NOT_SUPPORTED 2
  98
  99 /* Processor-specific failure code.  */
 100 #define GFC_FAILURE 42
 101
 102 extern void get_environment_variable_i4 (char *, char *, GFC_INTEGER_4 *,
 103                                          GFC_INTEGER_4 *, GFC_LOGICAL_4 *,
 104                                          gfc_charlen_type, gfc_charlen_type);
 105 iexport_proto(get_environment_variable_i4);
 106
 107 void
 108 get_environment_variable_i4 (char *name, char *value, GFC_INTEGER_4 *length,
 109                              GFC_INTEGER_4 *status, GFC_LOGICAL_4 *trim_name,
 110                              gfc_charlen_type name_len,
 111                              gfc_charlen_type value_len)
 112 {
 113   int stat = GFC_SUCCESS, res_len = 0;
 114   char *name_nt;
 115   char *res;
 116
 117   if (name == NULL)
 118     runtime_error ("Name is required for get_environment_variable.");
 119
 120   if (value == NULL && length == NULL && status == NULL && trim_name == NULL)
 121     return;
 122
 123   if (name_len < 1)
 124     runtime_error ("Zero-length string passed as name to "
 125                    "get_environment_variable.");
 126
 127   if (value != NULL)
 128     {
 129       if (value_len < 1)
 130         runtime_error ("Zero-length string passed as value to "
 131                        "get_environment_variable.");
 132       else
 133         memset (value, ' ', value_len); /* Blank the string.  */
 134     }
 135
 136   if ((!trim_name) || *trim_name)
 137     {
 138       /* Trim trailing spaces from name.  */
 139       while (name_len > 0 && name[name_len - 1] == ' ')
 140         name_len--;
 141     }
 142   /* Make a null terminated copy of the name.  */
 143   name_nt = gfc_alloca (name_len + 1);
 144   memcpy (name_nt, name, name_len);
 145   name_nt[name_len] = '\0';
 146
 147   res = getenv(name_nt);
 148
 149   if (res == NULL)
 150     stat = GFC_NAME_DOES_NOT_EXIST;
 151   else
 152     {
 153       res_len = strlen(res);
 154       if (value != NULL)
 155         {
 156           if (value_len < res_len)
 157             {
 158               memcpy (value, res, value_len);
 159               stat = GFC_VALUE_TOO_SHORT;
 160             }
 161           else
 162             memcpy (value, res, res_len);
 163         }
 164     }
 165
 166   if (status != NULL)
 167     *status = stat;
 168
 169   if (length != NULL)
 170     *length = res_len;
 171 }
 172 iexport(get_environment_variable_i4);
 173
 174
 175 /* INTEGER*8 wrapper for get_environment_variable.  */
 176
 177 extern void get_environment_variable_i8 (char *, char *, GFC_INTEGER_8 *,
 178                                          GFC_INTEGER_8 *, GFC_LOGICAL_8 *,
 179                                          gfc_charlen_type, gfc_charlen_type);
 180 export_proto(get_environment_variable_i8);
 181
 182 void
 183 get_environment_variable_i8 (char *name, char *value, GFC_INTEGER_8 *length,
 184                              GFC_INTEGER_8 *status, GFC_LOGICAL_8 *trim_name,
 185                              gfc_charlen_type name_len,
 186                              gfc_charlen_type value_len)
 187 {
 188   GFC_INTEGER_4 length4, status4;
 189   GFC_LOGICAL_4 trim_name4;
 190
 191   if (trim_name)
 192     trim_name4 = *trim_name;
 193
 194   get_environment_variable_i4 (name, value, &length4, &status4,
 195                                &trim_name4, name_len, value_len);
 196
 197   if (length)
 198     *length = length4;
 199
 200   if (status)
 201     *status = status4;
 202 }