Add testing of maximum size for files generated by solutions.

Author: giomasce

cmstestsuite/Tests.py

@@ -4,7 +4,7 @@
 # Contest Management System - http://cms-dev.github.io/
 # Copyright © 2012 Bernard Blackham <bernard@largestprime.net>
 # Copyright © 2013-2015 Stefano Maggiolo <s.maggiolo@gmail.com>
-# Copyright © 2014 Giovanni Mascellani <mascellani@poisson.phc.unipi.it>
+# Copyright © 2014-2015 Giovanni Mascellani <mascellani@poisson.phc.unipi.it>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License as
@@ -235,4 +235,11 @@
          languages=(LANG_C,),
          checks=[CheckOverallScore(0, 100)]),
 
+    # Write a huge file
+
+    Test('write-big-fileio',
+         task=batch_fileio, filename='write-big-fileio.%l',
+         languages=LANG_C,
+         checks=[CheckOverallScore(0, 100)]),
+
 ]

cmstestsuite/code/write-big-fileio.c

@@ -0,0 +1,35 @@
+#include <stdio.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+/* First we create a huge file in output.txt (2 GB). If the check on
+   file size is enforced, the write fails and we write a wrong
+   output. Otherwise we write correct output. */
+
+int main() {
+    int n, i;
+    FILE *in = fopen("input.txt", "r");
+    fscanf(in, "%d", &n);
+
+    // Seek is done in two steps so there are no probles even when
+    // type off_t is 4 bytes long. In this part everything is done
+    // calling directly syscalls because apparently libc does not
+    // properly report EFBIG errors.
+    int outfd = open("output.txt", O_WRONLY|O_CREAT|O_TRUNC, 0666);
+    lseek(outfd, 1024 * 1024 * 1024, SEEK_CUR);
+    lseek(outfd, 1024 * 1024 * 1024, SEEK_CUR);
+    i = write(outfd, "\0", 1);
+    close(outfd);
+
+    FILE *out = fopen("output.txt", "w");
+    if (i != 1) {
+        fprintf(out, "incorrect %d\n", n);
+        return 1;
+    } else {
+        fprintf(out, "correct %d\n", n);
+        return 0;
+    }
+}