erts: Add enif_getenv

to read OS environment variables in a safe and portable way.

4 files changed, 9 insertions, 1 deletions

diff --git a/erts/doc/src/erl_nif.xml b/erts/doc/src/erl_nif.xml
index 23c3d5fcee..3b77b1ffa0 100644
--- a/erts/doc/src/erl_nif.xml
+++ b/erts/doc/src/erl_nif.xml
@@ -791,6 +791,10 @@ typedef enum {
       and return true, or return false if <c>term</c> is not an unsigned integer or is
       outside the bounds of type <c>unsigned long</c>.</p></desc>
     </func>
+    <func><name><ret>int</ret><nametext>enif_getenv(const char* key, char* value, size_t *value_size)</nametext></name>
+      <fsummary>Get the value of an environment variable</fsummary>
+      <desc><p>Same as <seealso marker="erl_driver#erl_drv_getenv">erl_drv_getenv</seealso>.</p></desc>
+    </func>
     <func><name><ret>int</ret><nametext>enif_has_pending_exception(ErlNifEnv* env, ERL_NIF_TERM* reason)</nametext></name>
       <fsummary>Check if an exception has been raised</fsummary>
       <desc><p>Return true if a pending exception is associated
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index add4a66f90..d7a2076d85 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -1173,6 +1173,7 @@ ErlNifTid enif_thread_self(void) { return erl_drv_thread_self(); }
 int enif_equal_tids(ErlNifTid tid1, ErlNifTid tid2) { return erl_drv_equal_tids(tid1,tid2); }
 void enif_thread_exit(void *resp) { erl_drv_thread_exit(resp); }
 int enif_thread_join(ErlNifTid tid, void **respp) { return erl_drv_thread_join(tid,respp); }
+int enif_getenv(const char *key, char *value, size_t *value_size) { return erl_drv_getenv(key, value, value_size); }
 
 int enif_fprintf(void* filep, const char* format, ...) 
 { 
diff --git a/erts/emulator/beam/erl_nif.h b/erts/emulator/beam/erl_nif.h
index 7d880126f8..4cbfd8360b 100644
--- a/erts/emulator/beam/erl_nif.h
+++ b/erts/emulator/beam/erl_nif.h
@@ -48,9 +48,10 @@
 **           add ErlNifEntry options
 **           add ErlNifFunc flags
 ** 2.8: 18.0 add enif_has_pending_exception
+** 2.9: 18.2 enif_getenv
 */
 #define ERL_NIF_MAJOR_VERSION 2
-#define ERL_NIF_MINOR_VERSION 8
+#define ERL_NIF_MINOR_VERSION 9
 
 /*
  * The emulator will refuse to load a nif-lib with a major version
diff --git a/erts/emulator/beam/erl_nif_api_funcs.h b/erts/emulator/beam/erl_nif_api_funcs.h
index 2f2180e1aa..08b9afc6af 100644
--- a/erts/emulator/beam/erl_nif_api_funcs.h
+++ b/erts/emulator/beam/erl_nif_api_funcs.h
@@ -159,6 +159,7 @@ ERL_NIF_API_FUNC_DECL(int, enif_map_iterator_get_pair, (ErlNifEnv *env, ErlNifMa
 ERL_NIF_API_FUNC_DECL(ERL_NIF_TERM,enif_schedule_nif,(ErlNifEnv*,const char*,int,ERL_NIF_TERM (*)(ErlNifEnv*,int,const ERL_NIF_TERM[]),int,const ERL_NIF_TERM[]));
 ERL_NIF_API_FUNC_DECL(int, enif_has_pending_exception, (ErlNifEnv *env, ERL_NIF_TERM* reason));
 ERL_NIF_API_FUNC_DECL(ERL_NIF_TERM, enif_raise_exception, (ErlNifEnv *env, ERL_NIF_TERM reason));
+ERL_NIF_API_FUNC_DECL(int,enif_getenv,(const char* key, char* value, size_t* value_size));
 
 /*
 ** ADD NEW ENTRIES HERE (before this comment) !!!
@@ -310,6 +311,7 @@ ERL_NIF_API_FUNC_DECL(int,enif_is_on_dirty_scheduler,(ErlNifEnv*));
 #  define enif_schedule_nif ERL_NIF_API_FUNC_MACRO(enif_schedule_nif)
 #  define enif_has_pending_exception ERL_NIF_API_FUNC_MACRO(enif_has_pending_exception)
 #  define enif_raise_exception ERL_NIF_API_FUNC_MACRO(enif_raise_exception)
+#  define enif_getenv ERL_NIF_API_FUNC_MACRO(enif_getenv)
 
 /*
 ** ADD NEW ENTRIES HERE (before this comment)