src/corelib/tools/qvsnprintf.cpp
changeset 0 1918ee327afb
child 4 3b1da2848fc7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/corelib/tools/qvsnprintf.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,133 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qplatformdefs.h"
+
+#include "qbytearray.h"
+#include "qstring.h"
+
+#include "string.h"
+
+QT_BEGIN_NAMESPACE
+
+#ifndef QT_VSNPRINTF
+
+/*!
+    \relates QByteArray
+
+    A portable \c vsnprintf() function. Will call \c ::vsnprintf(), \c
+    ::_vsnprintf(), or \c ::vsnprintf_s depending on the system, or
+    fall back to an internal version.
+
+    \a fmt is the \c printf() format string. The result is put into
+    \a str, which is a buffer of at least \a n bytes.
+
+    The caller is responsible to call \c va_end() on \a ap.
+
+    \warning Since vsnprintf() shows different behavior on certain
+    platforms, you should not rely on the return value or on the fact
+    that you will always get a 0 terminated string back.
+
+    Ideally, you should never call this function but use QString::sprintf()
+    instead.
+
+    \sa qsnprintf(), QString::sprintf()
+*/
+
+int qvsnprintf(char *str, size_t n, const char *fmt, va_list ap)
+{
+    if (!str || !fmt)
+        return -1;
+
+    QString buf;
+    buf.vsprintf(fmt, ap);
+
+    QByteArray ba = buf.toLocal8Bit();
+
+    if (n > 0) {
+        size_t blen = qMin(size_t(ba.length()), size_t(n - 1));
+        memcpy(str, ba.constData(), blen);
+        str[blen] = '\0'; // make sure str is always 0 terminated
+    }
+
+    return ba.length();
+}
+
+#else
+
+QT_BEGIN_INCLUDE_NAMESPACE
+#include <stdio.h>
+QT_END_INCLUDE_NAMESPACE
+
+int qvsnprintf(char *str, size_t n, const char *fmt, va_list ap)
+{
+    return QT_VSNPRINTF(str, n, fmt, ap);
+}
+
+#endif
+
+/*!
+    \relates QByteArray
+
+    A portable snprintf() function, calls qvsnprintf.
+
+    \a fmt is the \c printf() format string. The result is put into
+    \a str, which is a buffer of at least \a n bytes.
+
+    \warning Call this function only when you know what you are doing
+    since it shows different behavior on certain platforms.
+    Use QString::sprintf() to format a string instead.
+
+    \sa qvsnprintf(), QString::sprintf()
+*/
+
+int qsnprintf(char *str, size_t n, const char *fmt, ...)
+{
+    va_list ap;
+    va_start(ap, fmt);
+
+    int ret = qvsnprintf(str, n, fmt, ap);
+    va_end(ap);
+
+    return ret;
+}
+
+QT_END_NAMESPACE