added test for opening a file more than once

lib/libc/tests/gen/multiopen.c

@@ -0,0 +1,49 @@
+/*
+ * This test tries to open the same file more than once.
+ *
+ * Devin Reade, 1997.
+ *
+ * $Id: multiopen.c,v 1.1 1997/07/27 23:45:04 gdr Exp $
+ */
+
+#ifdef __ORCAC__
+#pragma lint -1
+#pragma keep "testit"
+#endif
+
+#include <stdio.h>
+#ifdef __GNO__
+#include <unistd.h>
+#endif
+#include <errno.h>
+#include <stdlib.h>
+#include <fcntl.h>
+
+int
+main (int argc, char **argv) {
+  int fd1, fd2;
+  
+  if (argc != 2) {
+    printf("usage!\n");
+    exit(1);
+  }
+  
+  printf("trying first open\n");
+  fd1 = open(argv[1], O_RDONLY);
+  if (fd1 == -1) {
+    perror("open 1 failed\n");
+    exit (1);
+  }
+  
+  printf("trying second open\n");
+  fd2 = open(argv[1], O_RDONLY);
+  if (fd2 == -1) {
+    perror("open 2 failed\n");
+    exit (1);
+  }
+  
+  printf("done!\n");
+  close(fd1);
+  close(fd2);
+  return 0;
+}