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 Lesser General Public
  10 License as published by the Free Software Foundation; either
  11 version 2.1 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 Lesser General Public License for more details.
  17
  18 You should have received a copy of the GNU Lesser General Public
  19 License along with libgfor; see the file COPYING.LIB.  If not,
  20 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  21 Boston, MA 02111-1307, USA.  */
  22
  23 #include "config.h"
  24 #include <sys/types.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include "libgfortran.h"
  28
  29
  30 /* GETENV (NAME, VALUE), g77 intrinsic for retrieving the value of
  31  an environment variable. The name of the variable is specified in
  32  NAME, and the result is stored into VALUE.  */
  33
  34 void
  35 prefix(getenv) (char * name,
  36                 char * value,
  37                 gfc_charlen_type name_len,
  38                 gfc_charlen_type value_len)
  39 {
  40   char *name_nt;
  41   char *res = NULL;
  42   int res_len;
  43
  44   if (name == NULL || value == NULL)
  45     runtime_error ("Both arguments to getenv are mandatory.");
  46
  47   if (value_len < 1 || name_len < 1)
  48     runtime_error ("Zero length string(s) passed to getenv.");
  49   else
  50     memset (value, ' ', value_len); /* Blank the string.  */
  51
  52   /* Trim trailing spaces from name.  */
  53   while (name_len > 0 && name[name_len - 1] == ' ')
  54     name_len--;
  55
  56   /* Make a null terminated copy of the string.  */
  57   name_nt = gfc_alloca (name_len + 1);
  58   memcpy (name_nt, name, name_len);
  59   name_nt[name_len] = '\0';
  60
  61   res = getenv(name_nt);
  62
  63   /* If res is NULL, it means that the environment variable didn't
  64      exist, so just return.  */
  65   if (res == NULL)
  66     return;
  67
  68   res_len = strlen(res);
  69   if (value_len < res_len)
  70     memcpy (value, res, value_len);
  71   else
  72     memcpy (value, res, res_len);
  73 }
  74
  75
  76 /* GET_ENVIRONMENT_VARIABLE (name, [value, length, status, trim_name])
  77    is a F2003 intrinsic for getting an environment variable.  */
  78
  79 /* Status codes specifyed by the standard. */
  80 #define GFC_SUCCESS 0
  81 #define GFC_VALUE_TOO_SHORT -1
  82 #define GFC_NAME_DOES_NOT_EXIST 1
  83
  84 /* This is also specified by the standard and means that the
  85    processor doesn't support environment variables.  At the moment,
  86    gfortran doesn't use it.  */
  87 #define GFC_NOT_SUPPORTED 2
  88
  89 /* Processor-specific failure code.  */
  90 #define GFC_FAILURE 42
  91
  92 void
  93 prefix(get_environment_variable_i4)
  94   (
  95    char *name,
  96    char *value,
  97    GFC_INTEGER_4 *length,
  98    GFC_INTEGER_4 *status,
  99    GFC_LOGICAL_4 *trim_name,
 100    gfc_charlen_type name_len,
 101    gfc_charlen_type value_len)
 102 {
 103   int stat = GFC_SUCCESS, res_len = 0;
 104   char *name_nt;
 105   char *res;
 106
 107   if (name == NULL)
 108     runtime_error ("Name is required for get_environment_variable.");
 109
 110   if (value == NULL && length == NULL && status == NULL && trim_name == NULL)
 111     return;
 112
 113   if (name_len < 1)
 114     runtime_error ("Zero-length string passed as name to "
 115                    "get_environment_variable.");
 116
 117   if (value != NULL)
 118     {
 119       if (value_len < 1)
 120         runtime_error ("Zero-length string passed as value to "
 121                        "get_environment_variable.");
 122       else
 123         memset (value, ' ', value_len); /* Blank the string.  */
 124     }
 125
 126   if ((!trim_name) || *trim_name)
 127     {
 128       /* Trim trailing spaces from name.  */
 129       while (name_len > 0 && name[name_len - 1] == ' ')
 130         name_len--;
 131     }
 132   /* Make a null terminated copy of the name.  */
 133   name_nt = gfc_alloca (name_len + 1);
 134   memcpy (name_nt, name, name_len);
 135   name_nt[name_len] = '\0';
 136
 137   res = getenv(name_nt);
 138
 139   if (res == NULL)
 140     stat = GFC_NAME_DOES_NOT_EXIST;
 141   else
 142     {
 143       res_len = strlen(res);
 144       if (value != NULL)
 145         {
 146           if (value_len < res_len)
 147             {
 148               memcpy (value, res, value_len);
 149               stat = GFC_VALUE_TOO_SHORT;
 150             }
 151           else
 152             memcpy (value, res, res_len);
 153         }
 154     }
 155
 156   if (status != NULL)
 157     *status = stat;
 158
 159   if (length != NULL)
 160     *length = res_len;
 161 }
 162
 163
 164 /* INTEGER*8 wrapper for get_environment_variable.  */
 165
 166 void
 167 prefix(get_environment_variable_i8)
 168   (
 169    char *name,
 170    char *value,
 171    GFC_INTEGER_8 *length,
 172    GFC_INTEGER_8 *status,
 173    GFC_LOGICAL_8 *trim_name,
 174    gfc_charlen_type name_len,
 175    gfc_charlen_type value_len)
 176 {
 177   GFC_INTEGER_4 length4, status4;
 178   GFC_LOGICAL_4 trim_name4;
 179
 180   if (trim_name)
 181     trim_name4 = *trim_name;
 182
 183   prefix (get_environment_variable_i4) (name, value, &length4, &status4,
 184                                         &trim_name4, name_len, value_len);
 185
 186   if (length)
 187     *length = length4;
 188
 189   if (status)
 190     *status = status4;
 191 }