From 6119bdf90397bd89cc2e94eb286fd780dcae49e5 Mon Sep 17 00:00:00 2001
From: Steffen Vogel <post@steffenvogel.de>
Date: Mon, 20 Aug 2018 12:13:53 +0200
Subject: [PATCH] log: remove escape sequences from log output if not in a tty

---
 include/villas/log.h |  2 ++
 lib/log.c            | 21 +++++++++++++++------
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/include/villas/log.h b/include/villas/log.h
index bda5ee582..c5c299fa3 100644
--- a/include/villas/log.h
+++ b/include/villas/log.h
@@ -28,6 +28,7 @@ extern "C" {
 #endif
 
 #include <stdarg.h>
+#include <stdbool.h>
 #include <time.h>
 #include <sys/ioctl.h>
 
@@ -97,6 +98,7 @@ struct log {
 	const char *path;	/**< Path of the log file. */
 	char *prefix;		/**< Prefix each line with this string. */
 	int syslog;		/**< Whether or not to log to syslogd. */
+	bool tty;		/**< Is the log file a tty? */
 
 	FILE *file;		/**< Send all log output to this file / stdout / stderr. */
 };
diff --git a/lib/log.c b/lib/log.c
index e024cea26..6e149cf41 100644
--- a/lib/log.c
+++ b/lib/log.c
@@ -28,6 +28,7 @@
 #include <unistd.h>
 #include <syslog.h>
 #include <signal.h>
+#include <threads.h>
 
 #include <villas/config.h>
 #include <villas/log.h>
@@ -170,12 +171,14 @@ int log_open(struct log *l)
 	else
 		l->file = stderr;
 
-	l->state = STATE_OPENED;
+	l->tty = isatty(fileno(l->file));
 
 	if (l->syslog) {
 		openlog(NULL, LOG_PID, LOG_DAEMON);
 	}
 
+	l->state = STATE_OPENED;
+
 	debug(LOG_LOG | 5, "Log sub-system started: level=%d, faciltities=%#lx, path=%s", l->level, l->facilities, l->path);
 
 	return 0;
@@ -272,7 +275,7 @@ void log_print(struct log *l, const char *lvl, const char *fmt, ...)
 void log_vprint(struct log *l, const char *lvl, const char *fmt, va_list ap)
 {
 	struct timespec ts = time_now();
-	char *buf = alloc(512);
+	thread_local char buf[1024];
 
 	/* Optional prefix */
 	if (l->prefix)
@@ -288,11 +291,17 @@ void log_vprint(struct log *l, const char *lvl, const char *fmt, va_list ap)
 #ifdef ENABLE_OPAL_ASYNC
 	OpalPrint("VILLASnode: %s\n", buf);
 #endif
-	if (l->file)
+	if (l->file) {
+		if (l->tty == false)
+			decolor(buf);
+
 		fprintf(l->file, "%s\n", buf);
+	}
+
+	if (l->syslog) {
+		if (l->tty == true) // Only decolor if not done before
+			decolor(buf);
 
-	if (l->syslog)
 		vsyslog(LOG_INFO, fmt, ap);
-
-	free(buf);
+	}
 }