cpp: Add env var to control editinteractor debug

* lang/cpp/src/editinteractor.cpp (EditInteractor::Private::Private):
Read "GPGMEPP_INTERACTOR_DEBUG" env var.
(EditInteractor::Private::~Private): Close debug file.

--
While it was possible for the application to control the
debug through setDebugChannel it is often times helpful
to just debug without changing the application using
GPGME

1 files changed, 17 insertions, 2 deletions

diff --git a/lang/cpp/src/editinteractor.cpp b/lang/cpp/src/editinteractor.cpp
index f7c994a4..36d1be63 100644
--- a/lang/cpp/src/editinteractor.cpp
+++ b/lang/cpp/src/editinteractor.cpp
@@ -178,10 +178,25 @@ EditInteractor::Private::Private(EditInteractor *qq)
       error(),
       debug(nullptr)
 {
-
+    const char *debug_env = getenv("GPGMEPP_INTERACTOR_DEBUG");
+    if (!debug_env) {
+        return;
+    }
+    if (!strcmp(debug_env, "stdout")) {
+        debug = stdout;
+    } else if (!strcmp(debug_env, "stderr")) {
+        debug = stderr;
+    } else if (debug_env) {
+        debug = std::fopen(debug_env, "a+");
+    }
 }
 
-EditInteractor::Private::~Private() {}
+EditInteractor::Private::~Private()
+{
+    if (debug) {
+        std::fclose(debug);
+    }
+}
 
 EditInteractor::EditInteractor()
     : d(new Private(this))