Chapter 4 - I/O scheduling

chp4/inode.c

@@ -0,0 +1,39 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+/* get_inode - returns the inode of the file associated
+ * with the given file descriptor, or -1 on failure.
+ */
+int get_inode(int fd);
+
+int main(int argc, char *argv[]) {
+    if (argc < 2) {
+        fprintf(stderr, "usage: %s <file>\n", argv[0]);
+        return 1;
+    }
+
+    int fd = open(argv[1], O_RDONLY);
+    if (fd < 0) {
+        perror("open");
+        return 1;
+    }
+
+    int inode = get_inode(fd);
+    printf("%d\n", inode);
+    
+    return 0;
+}
+
+int get_inode(int fd) {
+    struct stat buf;
+
+    int ret = fstat(fd, &buf);
+    if (ret < 0) {
+        perror("fstat");
+        return -1;
+    }
+    return buf.st_ino;
+}