hostapd: Set stdout line-buffered

If hostapd will use stdout for debugging, set stdout to be line
buffered in case its output is redirected to a file. This allows
incremental output to be viewed immediately instead of at the file
buffering interval.

Signed-hostap: Paul Stewart <pstew@chromium.org>

hostapd/main.c

@@ -638,6 +638,8 @@ int main(int argc, char *argv[])
 
 	if (log_file)
 		wpa_debug_open_file(log_file);
+	else
+		wpa_debug_setup_stdout();
 #ifdef CONFIG_DEBUG_LINUX_TRACING
 	if (enable_trace_dbg) {
 		int tret = wpa_debug_open_linux_tracing();

src/utils/wpa_debug.c

@@ -574,6 +574,14 @@ void wpa_debug_close_file(void)
 #endif /* CONFIG_DEBUG_FILE */
 }
 
+
+void wpa_debug_setup_stdout(void)
+{
+#ifndef _WIN32
+	setvbuf(stdout, NULL, _IOLBF, 0);
+#endif /* _WIN32 */
+}
+
 #endif /* CONFIG_NO_STDOUT_DEBUG */
 
 

src/utils/wpa_debug.h

@@ -34,6 +34,7 @@ enum {
 #define wpa_hexdump_ascii_key(l,t,b,le) do { } while (0)
 #define wpa_debug_open_file(p) do { } while (0)
 #define wpa_debug_close_file() do { } while (0)
+#define wpa_debug_setup_stdout() do { } while (0)
 #define wpa_dbg(args...) do { } while (0)
 
 static inline int wpa_debug_reopen_file(void)
@@ -46,6 +47,7 @@ static inline int wpa_debug_reopen_file(void)
 int wpa_debug_open_file(const char *path);
 int wpa_debug_reopen_file(void);
 void wpa_debug_close_file(void);
+void wpa_debug_setup_stdout(void);
 
 /**
  * wpa_debug_printf_timestamp - Print timestamp for debug output