1 /* Implementation of the GETENV g77, and
2 GET_ENVIRONMENT_VARIABLE F2003, intrinsics.
3 Copyright (C) 2004-2023 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;
97 gfc_charlen_type res_len = 0;
98 char *name_nt;
99 char *res;
100
101 if (name == NULL)
102 runtime_error ("Name is required for get_environment_variable.");
103
104 if (value == NULL && length == NULL && status == NULL && trim_name == NULL)
105 return;
106
107 if (name_len < 1)
108 runtime_error ("Zero-length string passed as name to "
109 "get_environment_variable.");
110
111 if (value != NULL)
112 {
113 if (value_len > 0)
114 memset (value, ' ', value_len); /* Blank the string. */
115 }
116
117 if ((!trim_name) || *trim_name)
118 name_nt = fc_strdup (name, name_len);
119 else
120 name_nt = fc_strdup_notrim (name, name_len);
121
122 res = getenv(name_nt);
123
124 free (name_nt);
125
126 if (res == NULL)
127 stat = GFC_NAME_DOES_NOT_EXIST;
128 else
129 {
130 res_len = strlen(res);
131 if (value != NULL)
132 {
133 if (value_len < res_len)
134 {
135 memcpy (value, res, value_len);
136 stat = GFC_VALUE_TOO_SHORT;
137 }
138 else if (res_len > 0)
139 memcpy (value, res, res_len);
140 }
141 }
142
143 if (status != NULL)
144 *status = stat;
145
146 if (length != NULL)
147 *length = res_len;
148 }
149 iexport(get_environment_variable_i4);
150
151
152 /* INTEGER*8 wrapper for get_environment_variable. */
153
154 extern void get_environment_variable_i8 (char *, char *, GFC_INTEGER_8 *,
155 GFC_INTEGER_8 *, GFC_LOGICAL_8 *,
156 gfc_charlen_type, gfc_charlen_type);
157 export_proto(get_environment_variable_i8);
158
159 void
160 get_environment_variable_i8 (char *name, char *value, GFC_INTEGER_8 *length,
161 GFC_INTEGER_8 *status, GFC_LOGICAL_8 *trim_name,
162 gfc_charlen_type name_len,
163 gfc_charlen_type value_len)
164 {
165 GFC_INTEGER_4 length4, status4;
166 GFC_LOGICAL_4 trim_name4;
167
168 if (trim_name)
169 trim_name4 = *trim_name;
170
171 get_environment_variable_i4 (name, value, &length4, &status4,
172 trim_name ? &trim_name4 : NULL,
173 name_len, value_len);
174
175 if (length)
176 *length = length4;
177
178 if (status)
179 *status = status4;
180 }