dmesg: more colors, more fun

 * colorize subsystem prefix
 * colorize time
 * colorize by keywords (now "segfault" only)

Signed-off-by: Karel Zak <kzak@redhat.com>

1 files changed, 101 insertions, 21 deletions

diff --git a/sys-utils/dmesg.c b/sys-utils/dmesg.c
index 48c121fe8..685d415aa 100644
--- a/sys-utils/dmesg.c
+++ b/sys-utils/dmesg.c
@@ -58,6 +58,18 @@
 #define SYSLOG_ACTION_SIZE_BUFFER   10
 
 /*
+ * Colors
+ */
+#define DMESG_COLOR_SUBSYS	UL_COLOR_BROWN
+#define DMESG_COLOR_TIME	UL_COLOR_GREEN
+#define DMESG_COLOR_RELTIME	UL_COLOR_BOLD_GREEN
+#define DMESG_COLOR_ALERT	UL_COLOR_REVERSE UL_COLOR_RED
+#define DMESG_COLOR_CRIT	UL_COLOR_BOLD_RED
+#define DMESG_COLOR_ERR		UL_COLOR_RED
+#define DMESG_COLOR_WARN	UL_COLOR_BOLD
+#define DMESG_COLOR_SEGFAULT	UL_COLOR_HALFBRIGHT UL_COLOR_RED
+
+/*
  * Priority and facility names
  */
 struct dmesg_name {
@@ -175,22 +187,33 @@ struct dmesg_record {
 
 static int read_kmsg(struct dmesg_control *ctl);
 
-static int set_level_color(int log_level)
+static int set_level_color(int log_level, const char *mesg, size_t mesgsz)
 {
 	switch (log_level) {
 	case LOG_ALERT:
-		color_enable(UL_COLOR_BOLD_RED);
+		color_enable(DMESG_COLOR_ALERT);
 		return 0;
 	case LOG_CRIT:
-		color_enable(UL_COLOR_RED);
+		color_enable(DMESG_COLOR_CRIT);
 		return 0;
 	case LOG_ERR:
-		color_enable(UL_COLOR_BOLD);
+		color_enable(DMESG_COLOR_ERR);
+		return 0;
+	case LOG_WARNING:
+		color_enable(DMESG_COLOR_WARN);
 		return 0;
 	default:
 		break;
 	}
 
+	/* well, sometimes the messges contains important keywords, but in
+	 * non-warning/error messages
+	 */
+	if (memmem(mesg, mesgsz, "segfault at", 11)) {
+		color_enable(DMESG_COLOR_SEGFAULT);
+		return 0;
+	}
+
 	return 1;
 }
 
@@ -768,11 +791,32 @@ static double record_count_delta(struct dmesg_control *ctl,
 	return delta;
 }
 
+static const char *get_subsys_delimiter(const char *mesg, size_t mesg_size)
+{
+	const char *p = mesg;
+	size_t sz = mesg_size;
+
+	while (sz > 0) {
+		const char *d = strnchr(p, sz, ':');
+		if (!d)
+			return NULL;
+		sz -= d - p;
+		if (sz) {
+			if (isblank(*(d + 1)))
+				return d;
+			p = d + 1;
+		}
+	}
+	return NULL;
+}
+
 static void print_record(struct dmesg_control *ctl,
 			 struct dmesg_record *rec)
 {
 	char buf[256];
 	int has_color = 0;
+	const char *mesg;
+	size_t mesg_size;
 
 	if (!accept_record(ctl, rec))
 		return;
@@ -808,6 +852,8 @@ static void print_record(struct dmesg_control *ctl,
 	 * [sec.usec <delta>] or [ctime <delta>]
 	 */
 	if (ctl->delta) {
+		if (ctl->color)
+			color_enable(DMESG_COLOR_TIME);
 		if (ctl->ctime)
 			printf("[%s ", record_ctime(ctl, rec, buf, sizeof(buf)));
 		else if (ctl->notime)
@@ -816,12 +862,19 @@ static void print_record(struct dmesg_control *ctl,
 			printf("[%5d.%06d ", (int) rec->tv.tv_sec,
 					     (int) rec->tv.tv_usec);
 		printf("<%12.06f>] ", record_count_delta(ctl, rec));
+		if (ctl->color)
+			color_disable();
 
 	/*
 	 * [ctime]
 	 */
-	} else if (ctl->ctime)
+	} else if (ctl->ctime) {
+		if (ctl->color)
+			color_enable(DMESG_COLOR_TIME);
 		printf("[%s] ", record_ctime(ctl, rec, buf, sizeof(buf)));
+		if (ctl->color)
+			color_disable();
+	}
 
 	/*
 	 * [reltime]
@@ -835,13 +888,20 @@ static void print_record(struct dmesg_control *ctl,
 
 		if (cur.tm_min  != ctl->lasttm.tm_min ||
 		    cur.tm_hour != ctl->lasttm.tm_hour ||
-		    cur.tm_yday != ctl->lasttm.tm_yday)
+		    cur.tm_yday != ctl->lasttm.tm_yday) {
+			if (ctl->color)
+				color_enable(DMESG_COLOR_RELTIME);
 			printf("[%s] ", short_ctime(&cur, buf, sizeof(buf)));
-		else if (delta < 10)
-			printf("[  %+8.06f] ", delta);
-		else
-			printf("[ %+9.06f] ", delta);
-
+		} else {
+			if (ctl->color)
+				color_enable(DMESG_COLOR_TIME);
+			if (delta < 10)
+				printf("[  %+8.06f] ", delta);
+			else
+				printf("[ %+9.06f] ", delta);
+		}
+		if (ctl->color)
+			color_disable();
 		ctl->lasttm = cur;
 	}
 
@@ -854,20 +914,39 @@ static void print_record(struct dmesg_control *ctl,
 	 * the [sec.usec] string.
 	 */
 	if (ctl->method == DMESG_METHOD_KMSG &&
-	    !ctl->notime && !ctl->delta && !ctl->ctime && !ctl->reltime)
+	    !ctl->notime && !ctl->delta && !ctl->ctime && !ctl->reltime) {
+		if (ctl->color)
+			color_enable(DMESG_COLOR_TIME);
 		printf("[%5d.%06d] ", (int) rec->tv.tv_sec, (int) rec->tv.tv_usec);
+		if (ctl->color)
+			color_disable();
+	}
 
 mesg:
-	/* Change the output color for panic and error messages */
-	if (ctl->color)
-		has_color = set_level_color(rec->level) == 0;
-
-	safe_fwrite(rec->mesg, rec->mesg_size, stdout);
-
-	if (has_color)
-		color_disable();
+	mesg = rec->mesg;
+	mesg_size = rec->mesg_size;
+
+	/* Colorize output */
+	if (ctl->color) {
+		/* subsystem prefix */
+		const char *subsys = get_subsys_delimiter(mesg, mesg_size);
+		if (subsys) {
+			color_enable(DMESG_COLOR_SUBSYS);
+			safe_fwrite(mesg, subsys - mesg, stdout);
+			color_disable();
+
+			mesg_size -= subsys - mesg;
+			mesg = subsys;
+		}
+		/* error, alert .. etc. colors */
+		has_color = set_level_color(rec->level, mesg, mesg_size) == 0;
+		safe_fwrite(mesg, mesg_size, stdout);
+		if (has_color)
+			color_disable();
+	} else
+		safe_fwrite(mesg, mesg_size, stdout);
 
-	if (*(rec->mesg + rec->mesg_size - 1) != '\n')
+	if (*(mesg + mesg_size - 1) != '\n')
 		putchar('\n');
 }
 
@@ -1098,6 +1177,7 @@ int main(int argc, char *argv[])
 
 	static const ul_excl_t excl[] = {	/* rows and cols in in ASCII order */
 		{ 'C','D','E','c','n' },	/* clear,off,on,read-clear,level*/
+		{ 'L','r' },			/* color, raw */
 		{ 'S','w' },			/* syslog,follow */
 		{ 0 }
 	};