[Qemu-devel] [PATCH 1/6] monitor: return length of printed string via monitor_[v]printf

[Jan Kiszka]

This simply forwards the result of the internal vsnprintf to the callers
of monitor_printf and monitor_vprintf. When invoked over a QMP session
or in absence of an active monitor, -1 is returned.

CC: Luiz Capitulino <lcapitul...@redhat.com>
Signed-off-by: Jan Kiszka <jan.kis...@siemens.com>
---
 monitor.c   |   23 +++++++++++++++--------
 monitor.h   |    4 ++--
 qemu-tool.c |    6 ++++--
 3 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/monitor.c b/monitor.c
index ada51d0..a1bba27 100644
--- a/monitor.c
+++ b/monitor.c
@@ -270,29 +270,36 @@ static void monitor_puts(Monitor *mon, const char *str)
     }
 }
 
-void monitor_vprintf(Monitor *mon, const char *fmt, va_list ap)
+int monitor_vprintf(Monitor *mon, const char *fmt, va_list ap)
 {
     char buf[4096];
+    int ret;
 
-    if (!mon)
-        return;
-
+    if (!mon) {
+        return -1;
+    }
     mon_print_count_inc(mon);
 
     if (monitor_ctrl_mode(mon)) {
-        return;
+        return -1;
     }
 
-    vsnprintf(buf, sizeof(buf), fmt, ap);
+    ret = vsnprintf(buf, sizeof(buf), fmt, ap);
     monitor_puts(mon, buf);
+
+    return ret;
 }
 
-void monitor_printf(Monitor *mon, const char *fmt, ...)
+int monitor_printf(Monitor *mon, const char *fmt, ...)
 {
     va_list ap;
+    int ret;
+
     va_start(ap, fmt);
-    monitor_vprintf(mon, fmt, ap);
+    ret = monitor_vprintf(mon, fmt, ap);
     va_end(ap);
+
+    return ret;
 }
 
 void monitor_print_filename(Monitor *mon, const char *filename)
diff --git a/monitor.h b/monitor.h
index 4f2d328..873ba22 100644
--- a/monitor.h
+++ b/monitor.h
@@ -52,9 +52,9 @@ int monitor_read_bdrv_key_start(Monitor *mon, 
BlockDriverState *bs,
 
 int monitor_get_fd(Monitor *mon, const char *fdname);
 
-void monitor_vprintf(Monitor *mon, const char *fmt, va_list ap)
+int monitor_vprintf(Monitor *mon, const char *fmt, va_list ap)
     GCC_FMT_ATTR(2, 0);
-void monitor_printf(Monitor *mon, const char *fmt, ...) GCC_FMT_ATTR(2, 3);
+int monitor_printf(Monitor *mon, const char *fmt, ...) GCC_FMT_ATTR(2, 3);
 void monitor_print_filename(Monitor *mon, const char *filename);
 void monitor_flush(Monitor *mon);
 
diff --git a/qemu-tool.c b/qemu-tool.c
index eb89fe0..b0a032d7b 100644
--- a/qemu-tool.c
+++ b/qemu-tool.c
@@ -44,12 +44,14 @@ void monitor_set_error(Monitor *mon, QError *qerror)
 {
 }
 
-void monitor_vprintf(Monitor *mon, const char *fmt, va_list ap)
+int monitor_vprintf(Monitor *mon, const char *fmt, va_list ap)
 {
+    return -1;
 }
 
-void monitor_printf(Monitor *mon, const char *fmt, ...)
+int monitor_printf(Monitor *mon, const char *fmt, ...)
 {
+    return -1;
 }
 
 void monitor_print_filename(Monitor *mon, const char *filename)
-- 
1.7.3.4