main: must check pipe status on very top of program

Author: mofosyne

examples/main/main.cpp

@@ -120,6 +120,12 @@ static void llama_log_callback_logTee(ggml_log_level level, const char * text, v
 }
 
 int main(int argc, char ** argv) {
+#ifndef _MSC_VER
+    // Check if we have an external attachment to a file descriptor for out of band control tokens (e.g. bash `3>/dev/null` )
+    // Placed here to avoid file descriptor being polluted by gpt_params_parse() opening files
+    const bool control_token_file_descriptor_is_attached = fcntl(CONTROL_TOKEN_FILENO, F_GETFL) != -1;
+#endif
+
     gpt_params params;
     g_params = &params;
 
@@ -128,6 +134,16 @@ int main(int argc, char ** argv) {
     }
     llama_sampling_params & sparams = params.sparams;
 
+    const bool control_token_allowed_on_standard_stream = !params.conversation && sparams.grammar.empty();
+
+#ifndef _MSC_VER
+    // Merge normal token stream and control token streams together only if not in conversation or grammar mode
+    if (control_token_allowed_on_standard_stream && !control_token_file_descriptor_is_attached) {
+        // Duplicate stdout file descriptor to control token file descriptor to merge the two streams
+        dup2(STDOUT_FILENO, CONTROL_TOKEN_FILENO);
+    }
+#endif
+
 #ifndef LOG_DISABLE_LOGS
     log_set_target(log_filename_generator("main", "log"));
     LOG_TEE("Log start\n");
@@ -530,17 +546,6 @@ int main(int argc, char ** argv) {
         exit(1);
     }
 
-    const bool control_token_allowed_on_standard_stream = !params.conversation && sparams.grammar.empty();
-
-#ifndef _MSC_VER
-    const bool control_token_descriptor_is_attached = fcntl(CONTROL_TOKEN_FILENO, F_GETFL) != -1;
-    if (control_token_allowed_on_standard_stream && !control_token_descriptor_is_attached) {
-        // Control Token File Descriptor has nothing attached to it so make control token file descriptor be an alias of stdout
-        // This is not done however if we are in conversation mode or grammar mode as that is typically discarded
-        dup2(STDOUT_FILENO, CONTROL_TOKEN_FILENO);
-    }
-#endif
-
     while ((n_remain != 0 && !is_antiprompt) || params.interactive) {
         // predict
         if (!embd.empty()) {
@@ -758,20 +763,18 @@ int main(int argc, char ** argv) {
                 // Console/Stream Output
                 if (!llama_token_is_control_token(llama_get_model(ctx), id)) {
                     // Stream Output Token To Standard Output
-                    fflush(stdout);
                     fprintf(stdout, "%s", token_str.c_str());
                 } else if (!params.ctrl_token_no_out) {
 #ifndef _MSC_VER
-                    if (control_token_descriptor_is_attached) {
+                    if (control_token_file_descriptor_is_attached) {
                         // Stream Control Token To Special Token Output. Useful for debugging control token behaviour
-                        ssize_t result = write(CONTROL_TOKEN_FILENO, token_str.c_str(), token_str.length());
-                        (void) result;
+                        fflush(stdout); // Ensure control token is always appended to stdout stream
+                        (void)! write(CONTROL_TOKEN_FILENO, token_str.c_str(), token_str.length());
                     } else
 #endif
                     if (control_token_allowed_on_standard_stream)
                     {
                         // Stream Control Token To Standard Output Stream
-                        fflush(stdout);
                         fprintf(stdout, "%s", token_str.c_str());
                     }
                 }