ncd: modules: add getenv

blog_channels.txt

@@ -139,3 +139,4 @@ NCDBuildProgram 4
 ncd_log 4
 ncd_log_msg 4
 ncd_buffer 4
+ncd_getenv 4

generated/blog_channel_ncd_getenv.h

@@ -0,0 +1,4 @@
+#ifdef BLOG_CURRENT_CHANNEL
+#undef BLOG_CURRENT_CHANNEL
+#endif
+#define BLOG_CURRENT_CHANNEL BLOG_CHANNEL_ncd_getenv

generated/blog_channels_defines.h

@@ -139,4 +139,5 @@
 #define BLOG_CHANNEL_ncd_log 138
 #define BLOG_CHANNEL_ncd_log_msg 139
 #define BLOG_CHANNEL_ncd_buffer 140
-#define BLOG_NUM_CHANNELS 141
+#define BLOG_CHANNEL_ncd_getenv 141
+#define BLOG_NUM_CHANNELS 142

generated/blog_channels_list.h

@@ -139,3 +139,4 @@
 {"ncd_log", 4},
 {"ncd_log_msg", 4},
 {"ncd_buffer", 4},
+{"ncd_getenv", 4},

ncd/CMakeLists.txt

@@ -181,6 +181,7 @@ add_library(ncdinterpreter
     modules/substr.c
     modules/log.c
     modules/buffer.c
+    modules/getenv.c
     ${NCD_ADDITIONAL_SOURCES}
 )
 target_link_libraries(ncdinterpreter

ncd/modules/getenv.c

@@ -0,0 +1,153 @@
+/**
+ * @file getenv.c
+ * @author Ambroz Bizjak <ambrop7@gmail.com>
+ * 
+ * @section LICENSE
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the author nor the
+ *    names of its contributors may be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * 
+ * @section DESCRIPTION
+ * 
+ * Synopsis:
+ *   getenv(string name)
+ * 
+ * Variables:
+ *   string (empty) - if the environment value exists, its value
+ *   string exists - "true" if the variable exists, "false" if not
+ */
+
+#include <stdlib.h>
+
+#include <misc/strdup.h>
+#include <ncd/NCDModule.h>
+#include <ncd/static_strings.h>
+#include <ncd/extra/value_utils.h>
+
+#include <generated/blog_channel_ncd_getenv.h>
+
+#define ModuleLog(i, ...) NCDModuleInst_Backend_Log((i), BLOG_CURRENT_CHANNEL, __VA_ARGS__)
+#define ModuleString(i, id) ((i)->m->group->strings[(id)])
+
+struct instance {
+    NCDModuleInst *i;
+    char *value;
+};
+
+enum {STRING_EXISTS};
+
+static const char *strings[] = {"exists", NULL};
+
+static void func_new (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params)
+{
+    struct instance *o = vo;
+    o->i = i;
+    
+    // check arguments
+    NCDValRef name_arg;
+    if (!NCDVal_ListRead(params->args, 1, &name_arg)) {
+        ModuleLog(i, BLOG_ERROR, "wrong arity");
+        goto fail0;
+    }
+    if (!NCDVal_IsString(name_arg)) {
+        ModuleLog(i, BLOG_ERROR, "wrong type");
+        goto fail0;
+    }
+    
+    o->value = NULL;
+    
+    if (NCDVal_StringHasNulls(name_arg)) {
+        goto out;
+    }
+    
+    NCDValNullTermString nts;
+    if (!NCDVal_StringNullTerminate(name_arg, &nts)) {
+        ModuleLog(i, BLOG_ERROR, "NCDVal_StringNullTerminate failed");
+        goto fail0;
+    }
+    
+    char *result = getenv(nts.data);
+    NCDValNullTermString_Free(&nts);
+    if (!result) {
+        goto out;
+    }
+    
+    o->value = b_strdup(result);
+    if (!o->value) {
+        ModuleLog(i, BLOG_ERROR, "b_strdup failed");
+        goto fail0;
+    }
+    
+out:    
+    // signal up
+    NCDModuleInst_Backend_Up(i);
+    return;
+    
+fail0:
+    NCDModuleInst_Backend_DeadError(i);
+}
+
+static void func_die (void *vo)
+{
+    struct instance *o = vo;
+    
+    // free value
+    if (o->value) {
+        BFree(o->value);
+    }
+    
+    NCDModuleInst_Backend_Dead(o->i);
+}
+
+static int func_getvar (void *vo, NCD_string_id_t name, NCDValMem *mem, NCDValRef *out)
+{
+    struct instance *o = vo;
+    
+    if (name == NCD_STRING_EMPTY && o->value) {
+        *out = NCDVal_NewString(mem, o->value);
+        return 1;
+    }
+    
+    if (name == ModuleString(o->i, STRING_EXISTS)) {
+        *out = ncd_make_boolean(mem, !!o->value, o->i->params->iparams->string_index);
+        return 1;
+    }
+    
+    return 0;
+}
+
+static struct NCDModule modules[] = {
+    {
+        .type = "getenv",
+        .func_new2 = func_new,
+        .func_die = func_die,
+        .func_getvar2 = func_getvar,
+        .alloc_size = sizeof(struct instance)
+    }, {
+        .type = NULL
+    }
+};
+
+const struct NCDModuleGroup ncdmodule_getenv = {
+    .modules = modules,
+    .strings = strings
+};

ncd/modules/modules.h

@@ -79,6 +79,7 @@ extern const struct NCDModuleGroup ncdmodule_depend_scope;
 extern const struct NCDModuleGroup ncdmodule_substr;
 extern const struct NCDModuleGroup ncdmodule_log;
 extern const struct NCDModuleGroup ncdmodule_buffer;
+extern const struct NCDModuleGroup ncdmodule_getenv;
 #ifndef BADVPN_EMSCRIPTEN
 extern const struct NCDModuleGroup ncdmodule_regex_match;
 extern const struct NCDModuleGroup ncdmodule_run;
@@ -163,6 +164,7 @@ static const struct NCDModuleGroup *ncd_modules[] = {
     &ncdmodule_substr,
     &ncdmodule_log,
     &ncdmodule_buffer,
+    &ncdmodule_getenv,
 #ifndef BADVPN_EMSCRIPTEN
     &ncdmodule_regex_match,
     &ncdmodule_run,