From 7eced6773455e73b2867745fc0e95d7e315edd3b Mon Sep 17 00:00:00 2001
From: Mark Nellemann <mark.nellemann@gmail.com>
Date: Fri, 11 Nov 2022 08:51:27 +0100
Subject: [PATCH] Initial commit

---
 .gitignore |  2 ++
 Makefile   | 18 ++++++++++++++++
 test.c     | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 83 insertions(+)
 create mode 100644 Makefile
 create mode 100644 test.c

diff --git a/.gitignore b/.gitignore
index b24d71e..e9a2f4a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -48,3 +48,5 @@ Thumbs.db
 *.mov
 *.wmv
 
+# C objects
+*.o
\ No newline at end of file
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..e831373
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,18 @@
+# 
+# gcc -I/usr/include -L/usr/lib  -lperfstat -o test test.c
+
+CC=gcc
+CFLAGS=
+
+default: test
+
+%.0: %.c
+	$(CC) -c -o $@ $< $(CFLAGS)
+
+test: test.o 
+	gcc -lperfstat -o test test.o
+
+clean:
+	-rm -f test.o
+	-rm -f test
+
diff --git a/test.c b/test.c
new file mode 100644
index 0000000..7a77c7d
--- /dev/null
+++ b/test.c
@@ -0,0 +1,63 @@
+/*
+Repeatable prints disk statistics and sleeps for 10 seconds
+Modified example from: https://www.ibm.com/docs/en/aix/7.3?topic=interfaces-perfstat-disk-interface
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <libperfstat.h>
+
+int main(int argc, char* argv[]) {
+
+    int i, ret, tot;
+    perfstat_disk_t *statp;
+    perfstat_id_t first;
+
+    while(1) {
+
+        /* check how many perfstat_disk_t structures are available */
+        tot =  perfstat_disk(NULL, NULL, sizeof(perfstat_disk_t), 0);
+    
+        /* check for error */
+        if (tot < 0) {
+                perror("perfstat_disk");
+                exit(-1);
+        }
+        if (tot == 0) {
+                printf("No disks found in the system\n");
+                exit(-1);
+        }
+
+        /* allocate enough memory for all the structures */
+        statp = calloc(tot, sizeof(perfstat_disk_t));
+    
+        /* set name to first interface */
+        strcpy(first.name, FIRST_DISK);
+    
+        /* ask to get all the structures available in one call */
+        /* return code is number of structures returned */
+        ret = perfstat_disk(&first, statp, sizeof(perfstat_disk_t), tot);
+
+        /* check for error */
+        if (ret <= 0) {
+                perror("perfstat_disk");
+                exit(-1);
+        }
+
+        /* print statistics for each of the disks */
+        for (i = 0; i < ret; i++) {
+                printf("%s: %11u blocks of %11u bytes read, %11u blocks of %11u bytes written\n",
+                        statp[i].name,
+                        statp[i].rblks,
+                        statp[i].bsize,
+                        statp[i].wblks,
+                        statp[i].bsize
+                );
+        }
+
+        sleep(10);
+    }
+
+}