Implement freading and fwriting.

[gnulib.git] / tests / test-freading.c

diff --git a/tests/test-freading.c b/tests/test-freading.c
new file mode 100644 (file)
index 0000000..02414e5
--- /dev/null
+++ b/tests/test-freading.c
@@ -0,0 +1,111 @@
+/* Test of freading() function.
+   Copyright (C) 2007 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2007.  */
+
+#include <config.h>
+
+#include "freading.h"
+
+#include <stdlib.h>
+
+#define ASSERT(expr) if (!(expr)) abort ();
+
+#define TESTFILE "t-freading.tmp"
+
+int
+main ()
+{
+  FILE *fp;
+
+  /* Create a file with some contents.  Write-only file is never reading.  */
+  fp = fopen (TESTFILE, "w");
+  if (fp == NULL)
+    goto skip;
+  ASSERT (!freading (fp));
+  if (fwrite ("foobarsh", 1, 8, fp) < 8)
+    goto skip;
+  ASSERT (!freading (fp));
+  if (fclose (fp))
+    goto skip;
+
+  /* Open it in read-only mode.  Read-only file is always reading.  */
+  fp = fopen (TESTFILE, "r");
+  if (fp == NULL)
+    goto skip;
+  ASSERT (freading (fp));
+  if (fgetc (fp) != 'f')
+    goto skip;
+  ASSERT (freading (fp));
+  if (fseek (fp, 2, SEEK_CUR))
+    goto skip;
+  ASSERT (freading (fp));
+  if (fgetc (fp) != 'b')
+    goto skip;
+  ASSERT (freading (fp));
+  if (fseek (fp, 0, SEEK_END))
+    goto skip;
+  ASSERT (freading (fp));
+  if (fclose (fp))
+    goto skip;
+
+  /* Open it in read-write mode.  POSIX requires a reposition (fseek,
+     fsetpos, rewind) or EOF when transitioning from read to write;
+     freading is only deterministic after input or output, but this
+     test case should be portable even on open, after reposition, and
+     at EOF.  */
+  fp = fopen (TESTFILE, "r+");
+  if (fp == NULL)
+    goto skip;
+  ASSERT (!freading (fp));
+  if (fgetc (fp) != 'f')
+    goto skip;
+  ASSERT (freading (fp));
+  if (fseek (fp, 2, SEEK_CUR))
+    goto skip;
+  /* freading (fp)) is undefined here, but fwriting is false.  */
+  if (fgetc (fp) != 'b')
+    goto skip;
+  ASSERT (freading (fp));
+  if (fseek (fp, 0, SEEK_CUR) != 0)
+    goto skip;
+  if (fputc ('z', fp) != 'z')
+    goto skip;
+  ASSERT (!freading (fp));
+  if (fseek (fp, 0, SEEK_END))
+    goto skip;
+  ASSERT (!freading (fp));
+  if (fclose (fp))
+    goto skip;
+
+  /* Open it in append mode.  Write-only file is never reading.  */
+  fp = fopen (TESTFILE, "a");
+  if (fp == NULL)
+    goto skip;
+  ASSERT (!freading (fp));
+  if (fwrite ("bla", 1, 3, fp) < 3)
+    goto skip;
+  ASSERT (!freading (fp));
+  if (fclose (fp))
+    goto skip;
+
+  return 0;
+
+ skip:
+  fprintf (stderr, "Skipping test: file operations failed.\n");
+  return 77;
+}