1 files changed, 59 insertions, 0 deletions
diff --git a/toys/lsb/dmesg.c b/toys/lsb/dmesg.c
new file mode 100644
index 00000000..95b023d6
--- /dev/null
+++ b/toys/lsb/dmesg.c
@@ -0,0 +1,59 @@
+/* vi: set sw=4 ts=4:
+ *
+ * dmesg.c - display/control kernel ring buffer.
+ *
+ * Copyright 2006, 2007 Rob Landley <rob@landley.net>
+ *
+ * Not in SUSv3.
+
+USE_DMESG(NEWTOY(dmesg, "s#n#c", TOYFLAG_BIN))
+
+config DMESG
+	bool "dmesg"
+	default y
+	help
+	  usage: dmesg [-n level] [-s bufsize] | -c
+
+	  Print or control the kernel ring buffer.
+
+	  -n	Set kernel logging level (1-9).
+	  -s	Size of buffer to read (in bytes), default 16384.
+	  -c	Clear the ring buffer after printing.
+*/
+
+#include "toys.h"
+#include <sys/klog.h>
+
+DEFINE_GLOBALS(
+	long level;
+	long size;
+)
+
+#define TT this.dmesg
+
+void dmesg_main(void)
+{
+	// For -n just tell kernel to which messages to keep.
+	if (toys.optflags & 2) {
+		if (klogctl(8, NULL, TT.level))
+			error_exit("klogctl");
+	} else {
+		int size, i, last = '\n';
+		char *data;
+
+		// Figure out how much data we need, and fetch it.
+		size = TT.size;
+		if (size<2) size = 16384;
+		data = xmalloc(size);
+		size = klogctl(3 + (toys.optflags&1), data, size);
+		if (size < 0) error_exit("klogctl");
+
+		// Display data, filtering out level markers.
+		for (i=0; i<size; ) {
+			if (last=='\n' && data[i]=='<') i += 3;
+			else xputc(last = data[i++]);
+		}
+		if (last!='\n') xputc('\n');
+		if (CFG_TOYBOX_FREE) free(data);
+	}
+}