initial tree

1 files changed, 47 insertions, 0 deletions

diff --git a/interrupts.c b/interrupts.c
new file mode 100644
index 0000000..2755ccf
--- /dev/null
+++ b/interrupts.c
@@ -0,0 +1,47 @@
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+#include "common.h"
+
+int interrupts(int argc, char **argv) {
+	FILE *f;
+	char buff[256];
+	if(argc > 1) {
+		if(!strcmp(argv[1], "config")) {
+			puts("graph_title Interrupts & context switches\n"
+				"graph_args --base 1000 -l 0\n"
+				"graph_vlabel interrupts & ctx switches / ${graph_period}\n"
+				"graph_category system\n"
+				"graph_info This graph shows the number of interrupts and context switches on the system. These are typically high on a busy system.\n"
+				"intr.info Interrupts are events that alter sequence of instructions executed by a processor. They can come from either hardware (exceptions, NMI, IRQ) or software.");
+			puts("ctx.info A context switch occurs when a multitasking operatings system suspends the currently running process, and starts executing another.\n"
+				"intr.label interrupts\n"
+				"ctx.label context switches\n"
+				"intr.type DERIVE\n"
+				"ctx.type DERIVE\n"
+				"intr.max 100000\n"
+				"ctx.max 100000\n"
+				"intr.min 0\n"
+				"ctx.min 0");
+			return 0;
+		}
+		if(!strcmp(argv[1], "autoconf")) {
+			if(0 == access("/proc/stat", R_OK))
+				return writeyes();
+			else
+				return writeno("/proc/stat not readable");
+		}
+	}
+	if(!(f=fopen("/proc/stat", "r"))) {
+		fputs("cannot open /proc/stat\n", stderr);
+		return 1;
+	}
+	while(fgets(buff, 256, f)) {
+		if(!strncmp(buff, "intr ", 5))
+			printf("intr.value %s", buff+5);
+		else if(!strncmp(buff, "ctxt ", 5))
+			printf("ctx.value %s", buff+5);
+	}
+	fclose(f);
+	return 0;
+}