Add fmemopen(3), an interface to get a FILE * from a buffer in memory, along

with the respective regression test.
See http://pubs.opengroup.org/onlinepubs/9699919799/functions/fmemopen.html

Reviewed by:	cognet
Approved by:	cognet

2 files changed, 153 insertions, 0 deletions

diff --git a/tools/regression/lib/libc/stdio/test-fmemopen.c b/tools/regression/lib/libc/stdio/test-fmemopen.c
new file mode 100644
index 0000000..d9c1276
--- /dev/null
+++ b/tools/regression/lib/libc/stdio/test-fmemopen.c
@@ -0,0 +1,143 @@
+/*-
+Copyright (C) 2013 Pietro Cerutti <gahr@FreeBSD.org>
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+1. Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.
+*/
+
+/*
+ * Test basic FILE * functions (fread, fwrite, fseek, fclose) against
+ * a FILE * retrieved using fmemopen()
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <strings.h>
+
+void
+test_preexisting ()
+{
+	/* 
+	 * use a pre-existing buffer
+	 */
+
+	char buf[512];
+	char buf2[512];
+	char str[]  = "Test writing some stuff";
+	char str2[] = "AAAAAAAAA";
+	char str3[] = "AAAA writing some stuff";
+	FILE *fp;
+	size_t nofw, nofr;
+	int rc;
+
+	/* open a FILE * using fmemopen */
+	fp = fmemopen (buf, sizeof buf, "w");
+	assert (fp != NULL);
+
+	/* write to the buffer */
+	nofw = fwrite (str, 1, sizeof str, fp);
+	assert (nofw == sizeof str);
+
+	/* close the FILE * */
+	rc = fclose (fp);
+	assert (rc == 0);
+
+	/* re-open the FILE * to read back the data */
+	fp = fmemopen (buf, sizeof buf, "r");
+	assert (fp != NULL);
+
+	/* read from the buffer */
+	bzero (buf2, sizeof buf2);
+	nofr = fread (buf2, 1, sizeof buf2, fp);
+	assert (nofr == sizeof buf2);
+
+	/* since a write on a FILE * retrieved by fmemopen
+	 * will add a '\0' (if there's space), we can check
+	 * the strings for equality */
+	assert (strcmp(str, buf2) == 0);
+
+	/* close the FILE * */
+	rc = fclose (fp);
+	assert (rc == 0);
+
+	/* now open a FILE * on the first 4 bytes of the string */
+	fp = fmemopen (str, 4, "w");
+	assert (fp != NULL);
+
+	/* try to write more bytes than we shoud, we'll get a short count (4) */
+	nofw = fwrite (str2, 1, sizeof str2, fp);
+	assert (nofw == 4);
+
+	/* close the FILE * */
+	rc = fclose (fp);
+
+	/* check that the string was not modified after the first 4 bytes */
+	assert (strcmp (str, str3) == 0);
+}
+
+void
+test_autoalloc ()
+{
+	/* 
+	 * let fmemopen allocate the buffer
+	 */
+
+	char str[] = "A quick test";
+	FILE *fp;
+	long pos;
+	size_t nofw, nofr, i;
+	int rc;
+
+	/* open a FILE * using fmemopen */
+	fp = fmemopen (NULL, 512, "w");
+	assert (fp != NULL);
+
+	/* fill the buffer */
+	for (i = 0; i < 512; i++) {
+		nofw = fwrite ("a", 1, 1, fp);
+		assert (nofw == 1);
+	}
+
+	/* get the current position into the stream */
+	pos = ftell (fp);
+	assert (pos == 512);
+
+	/* try to write past the end, we should get a short object count (0) */
+	nofw = fwrite ("a", 1, 1, fp);
+	assert (nofw == 0);
+
+	/* close the FILE * */
+	rc = fclose (fp);
+	assert (rc == 0);
+}
+
+int
+main (void)
+{
+	test_autoalloc   ();
+	test_preexisting ();
+	return (0);
+}
diff --git a/tools/regression/lib/libc/stdio/test-fmemopen.t b/tools/regression/lib/libc/stdio/test-fmemopen.t
new file mode 100644
index 0000000..8bdfd03
--- /dev/null
+++ b/tools/regression/lib/libc/stdio/test-fmemopen.t
@@ -0,0 +1,10 @@
+#!/bin/sh
+# $FreeBSD$
+
+cd `dirname $0`
+
+executable=`basename $0 .t`
+
+make $executable 2>&1 > /dev/null
+
+exec ./$executable