From 370d79ce04e038844d7d9513a5c039db4c31f892 Mon Sep 17 00:00:00 2001
From: Tim Janik <timj@gnu.org>
Date: Sat, 25 Jul 2026 23:29:12 +0200
Subject: [PATCH] add -o/--output flag to write transcription text to a file

When -o <path> is given, the CLI writes only the transcribed text (no
metadata, no timestamps, no timings) to that file. Stdout is unchanged.
In batch mode each utterance's text goes on its own line.

 examples/cli/main.cpp | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)
---
 examples/cli/main.cpp | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/examples/cli/main.cpp b/examples/cli/main.cpp
index df820403..5803f0d0 100644
--- a/examples/cli/main.cpp
+++ b/examples/cli/main.cpp
@@ -204,6 +204,7 @@ struct cli_args {
     bool                       quiet        = false;
     bool                       list_devices = false;  // --list-devices: print devices and exit
     bool                       batch_jsonl  = false;  // --batch-jsonl: output JSONL
+    std::string                output_path;            // -o: write raw text here
     int                        repeat       = 1;
     int                        n_threads    = 0;      // 0 = library default (all cores)
     int                        n_ctx        = 0;      // 0 = model's true max; >0 lowers the cap
@@ -282,6 +283,7 @@ void print_usage(const char * argv0) {
                  "  --target-language ISO target language for translation (e.g. de, es, fr)\n"
                  "  -q, --quiet           suppress library log output\n"
                  "  -r, --repeat N        run N times per file (benchmark)\n"
+                 "  -o, --output PATH     write transcribed text to PATH (stdout unchanged)\n"
                  "  --threads N           CPU threads (default: all cores)\n"
                  "  --n-ctx N             session context/KV cap in tokens (bounds decoder\n"
                  "                        KV memory; cannot extend the model): 0 = model\n"
@@ -528,6 +530,12 @@ bool parse_args(int argc, char ** argv, cli_args & out) {
                 std::fprintf(stderr, "error: --batch-size must be >= 0\n");
                 return false;
             }
+        } else if (a == "-o" || a == "--output") {
+            const char * v = take_value(a.c_str());
+            if (!v) {
+                return false;
+            }
+            out.output_path = v;
         } else if (a == "--initial-prompt") {
             const char * v = take_value(a.c_str());
             if (!v) {
@@ -688,6 +696,20 @@ void log_cb(transcribe_log_level level, const char * msg, void * userdata) {
     std::fprintf(stderr, "%s %s%s", prefix, msg, (msg && *msg && msg[std::strlen(msg) - 1] == '\n') ? "" : "\n");
 }
 
+// Write transcription text to the output file if -o was given.
+// Appends so it works for both single-file and batch mode.
+static void write_output_file(const std::string & path, const char * text) {
+    if (path.empty() || text == nullptr || text[0] == '\0') {
+        return;
+    }
+    std::ofstream fout(path, std::ios::binary | std::ios::app);
+    if (!fout) {
+        std::fprintf(stderr, "error: cannot open %s for writing\n", path.c_str());
+    } else {
+        fout << text << '\n';
+    }
+}
+
 }  // namespace
 
 int main(int argc, char ** argv) {
@@ -957,6 +979,7 @@ int main(int argc, char ** argv) {
                             std::printf("  ERROR: %s\n", transcribe_status_string(ust));
                         }
                     }
+                    write_output_file(args.output_path, text);
                     std::fflush(stdout);
                 }
             }
@@ -1095,6 +1118,7 @@ int main(int argc, char ** argv) {
                         std::printf("  ERROR: %s\n", transcribe_status_string(run_st));
                     }
                 }
+                write_output_file(args.output_path, text);
                 std::fflush(stdout);
             }
         }
@@ -1341,6 +1365,7 @@ int main(int argc, char ** argv) {
         if (result_present) {
             const char * text = transcribe_full_text(ctx);
             std::printf("text: %s\n", (text && *text) ? text : "(empty)");
+            write_output_file(args.output_path, text);
 
             // A truncated decode hit the model's context/output budget before
             // end-of-stream; the text above is incomplete.