main: remove --ctrl-token-fd-out in favor for fcntl() based detection

common/common.cpp

@@ -909,10 +909,6 @@ bool gpt_params_find_arg(int argc, char ** argv, const std::string & arg, gpt_pa
         params.ctrl_token_no_out = true;
         return true;
     }
-    if (arg == "--ctrl-token-fd-out") {
-        params.ctrl_token_fd_out = true;
-        return true;
-    }
     if (arg == "--embedding") {
         params.embedding = true;
         return true;
@@ -1442,9 +1438,6 @@ void gpt_print_usage(int /*argc*/, char ** argv, const gpt_params & params) {
     printf("  -i, --interactive     run in interactive mode\n");
     printf("  --interactive-specials allow special tokens in user text, in interactive mode\n");
     printf("  --ctrl-token-no-out   control tokens output disabled\n");
-#if defined (__unix__) || (defined (__APPLE__) && defined (__MACH__))
-    printf("  --ctrl-token-fd-out   control tokens sent to file descriptor 3 out of band\n");
-#endif
     printf("  -cnv, --conversation  run in conversation mode (does not print special tokens and suffix/prefix)\n");
     printf("  -ins, --instruct      run in instruction mode (use with Alpaca models)\n");
     printf("  -cml, --chatml        run in chatml mode (use with ChatML-compatible models)\n");

common/common.h

@@ -143,7 +143,6 @@ struct gpt_params {
     bool interactive       = false; // interactive mode
     bool interactive_specials = false; // whether to allow special tokens from user, during interactive mode
     bool ctrl_token_no_out = false; // disable control token output
-    bool ctrl_token_fd_out = false; // enable control token output and redirect it to file descriptor 3
     bool conversation      = false; // conversation mode (does not print special tokens and suffix/prefix)
     bool chatml            = false; // chatml mode (used for models trained on chatml syntax)
     bool prompt_cache_all  = false; // save user input and generations to prompt cache

examples/main/main.cpp

@@ -18,7 +18,8 @@
 #if defined (__unix__) || (defined (__APPLE__) && defined (__MACH__))
 #include <signal.h>
 #include <unistd.h>
-#define CONTROL_TOKEN_FILE_DESCRIPTOR (3)
+#include <fcntl.h>
+#define CONTROL_TOKEN_FILENO (3)
 #elif defined (_WIN32)
 #define WIN32_LEAN_AND_MEAN
 #ifndef NOMINMAX
@@ -529,6 +530,14 @@ int main(int argc, char ** argv) {
         exit(1);
     }
 
+#ifndef _MSC_VER
+    if (fcntl(CONTROL_TOKEN_FILENO, F_GETFL) == -1) {
+        // Control Token File Descriptor has nothing attached to it
+        // make control token file descriptor be an alias of stdout
+        dup2(STDOUT_FILENO, CONTROL_TOKEN_FILENO);
+    }
+#endif
+
     while ((n_remain != 0 && !is_antiprompt) || params.interactive) {
         // predict
         if (!embd.empty()) {
@@ -746,23 +755,23 @@ 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 (params.ctrl_token_fd_out) {
-                        // Stream Control Token To Special Token Output. Useful for debugging control token behaviour
-                        ssize_t result = write(CONTROL_TOKEN_FILE_DESCRIPTOR, token_str.c_str(), token_str.length());
-                        (void) result;
-                    }
-                    else
-#endif
                     if (!params.conversation && sparams.grammar.empty())
                     {
-                        // Stream Control Token To Standard Output as long as we are not in a conversation or grammar output
+                        // Stream Control Token To Special Token Output. Useful for debugging control token behaviour
+                        fflush(stdout);
                         fprintf(stdout, "%s", token_str.c_str());
                     }
+#ifndef _MSC_VER
+                    else {
+                        // 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;
+                    }
+#endif
                 }
-
                 // Record Displayed Tokens To Log
                 // Note: Generated tokens are created one by one hence this check
                 if (embd.size() > 1) {