From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:52943)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <alex.bennee@linaro.org>) id 1WTZsU-00077B-FX
	for qemu-devel@nongnu.org; Fri, 28 Mar 2014 12:43:39 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <alex.bennee@linaro.org>) id 1WTZsP-0002jd-D1
	for qemu-devel@nongnu.org; Fri, 28 Mar 2014 12:43:34 -0400
Received: from static.88-198-71-155.clients.your-server.de
	([88.198.71.155]:56333 helo=socrates.bennee.com)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <alex.bennee@linaro.org>) id 1WTZsP-0002jQ-6A
	for qemu-devel@nongnu.org; Fri, 28 Mar 2014 12:43:29 -0400
From: =?UTF-8?q?Alex=20Benn=C3=A9e?= <alex.bennee@linaro.org>
Date: Fri, 28 Mar 2014 16:43:24 +0000
Message-Id: <1396025007-27592-5-git-send-email-alex.bennee@linaro.org>
In-Reply-To: <1396025007-27592-1-git-send-email-alex.bennee@linaro.org>
References: <1396025007-27592-1-git-send-email-alex.bennee@linaro.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Subject: [Qemu-devel] [PATCH v2 4/7] qemu-log: support simple pid
	substitution in logfile
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: qemu-devel@nongnu.org
Cc: =?UTF-8?q?Alex=20Benn=C3=A9e?= <alex.bennee@linaro.org>

When debugging stuff that occurs over several forks it would be useful
not to keep overwriting the one logfile you've set-up. This allows a
simple %d to be included once in the logfile parameter which is
substituted with getpid().

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Leandro Dorileo <l@dorileo.org>

diff --git a/qemu-log.c b/qemu-log.c
index 83e0cb4..4dd530c 100644
--- a/qemu-log.c
+++ b/qemu-log.c
@@ -70,11 +70,24 @@ void do_qemu_set_log(int log_flags, bool use_own_buffers)
         qemu_log_close();
     }
 }
-
+/*
+ * Allow the user to include %d in their logfile which will be
+ * substituted with the current PID. This is useful for debugging many
+ * nested linux-user tasks but will result in lots of logs.
+ */
 void qemu_set_log_filename(const char *filename)
 {
     g_free(logfilename);
-    logfilename = g_strdup(filename);
+    if (g_strrstr(filename, "%d")) {
+        /* if we are going to format this we'd better validate first */
+        if (g_regex_match_simple("^[^%]+%d[^%]+$", filename, 0, 0)) {
+            logfilename = g_strdup_printf(filename, getpid());
+        } else {
+            g_error("Bad logfile format: %s", filename);
+        }
+    } else {
+        logfilename = g_strdup(filename);
+    }
     qemu_log_close();
     qemu_set_log(qemu_loglevel);
 }
-- 
1.9.1