Mercurial > sdl-ios-xcode
view docs/html/sdlwasinit.html @ 4355:9b464226e541 SDL-1.2
Fixed bug #855
Ludwig Nussel 2009-10-18 06:31:52 PDT
an mprotect call was added to fix bug 528. However that results in a buffer
that allows writing and code execution. Ie the no-execute security features of
modern operating systems are defeated this way. Two mprotect calls are needed.
One to make the buffer executable but not writeable when done and another one
to make the buffer writeable again if the content needs to be changed.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 18 Oct 2009 17:31:37 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_WasInit</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="General" HREF="general.html"><LINK REL="PREVIOUS" TITLE="SDL_Quit" HREF="sdlquit.html"><LINK REL="NEXT" TITLE="SDL_GetError" HREF="sdlgeterror.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >SDL Library Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="sdlquit.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlgeterror.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLWASINIT" ></A >SDL_WasInit</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN617" ></A ><H2 >Name</H2 >SDL_WasInit -- Check which subsystems are initialized</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN620" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN621" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >Uint32 <B CLASS="FSFUNC" >SDL_WasInit</B ></CODE >(Uint32 flags);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN627" ></A ><H2 >Description</H2 ><P ><TT CLASS="FUNCTION" >SDL_WasInit</TT > allows you to see which SDL subsytems have been <A HREF="sdlinit.html" >initialized</A >. <TT CLASS="PARAMETER" ><I >flags</I ></TT > is a bitwise OR'd combination of the subsystems you wish to check (see <A HREF="sdlinit.html" ><TT CLASS="FUNCTION" >SDL_Init</TT ></A > for a list of subsystem flags).</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN635" ></A ><H2 >Return Value</H2 ><P ><TT CLASS="FUNCTION" >SDL_WasInit</TT > returns a bitwised OR'd combination of the initialized subsystems.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN639" ></A ><H2 >Examples</H2 ><PRE CLASS="PROGRAMLISTING" > /* Here are several ways you can use SDL_WasInit() */ /* Get init data on all the subsystems */ Uint32 subsystem_init; subsystem_init=SDL_WasInit(SDL_INIT_EVERYTHING); if(subsystem_init&SDL_INIT_VIDEO) printf("Video is initialized.\n"); else printf("Video is not initialized.\n"); /* Just check for one specfic subsystem */ if(SDL_WasInit(SDL_INIT_VIDEO)!=0) printf("Video is initialized.\n"); else printf("Video is not initialized.\n"); /* Check for two subsystems */ Uint32 subsystem_mask=SDL_INIT_VIDEO|SDL_INIT_AUDIO; if(SDL_WasInit(subsystem_mask)==subsystem_mask) printf("Video and Audio initialized.\n"); else printf("Video and Audio not initialized.\n"); </PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN642" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlinit.html" ><TT CLASS="FUNCTION" >SDL_Init</TT ></A >, <A HREF="sdlinitsubsystem.html" ><TT CLASS="FUNCTION" >SDL_Subsystem</TT ></A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlquit.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlgeterror.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_Quit</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="general.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_GetError</TD ></TR ></TABLE ></DIV ></BODY ></HTML >