view docs/html/sdlcd.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_CD</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="CD-ROM"
HREF="cdrom.html"><LINK
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TITLE="SDL_CDClose"
HREF="sdlcdclose.html"><LINK
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TITLE="SDL_CDtrack"
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><BODY
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><HR
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><H1
><A
NAME="SDLCD"
></A
>SDL_CD</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN7566"
></A
><H2
>Name</H2
>SDL_CD&nbsp;--&nbsp;CDROM Drive Information</DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7569"
></A
><H2
>Structure Definition</H2
><PRE
CLASS="PROGRAMLISTING"
>typedef struct{
  int id;
  CDstatus status;
  int numtracks;
  int cur_track;
  int cur_frame;
  SDL_CDtrack track[SDL_MAX_TRACKS+1];
} SDL_CD;</PRE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7572"
></A
><H2
>Structure Data</H2
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN7574"
></A
><P
></P
><TABLE
BORDER="0"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>id</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Private drive identifier</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>status</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Drive <A
HREF="sdlcdstatus.html"
>status</A
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>numtracks</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Number of tracks on the CD</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>cur_track</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Current track</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>cur_frame</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Current frame offset within the track</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>track</I
></TT
>[SDL_MAX_TRACKS+1]</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Array of track descriptions. (see <A
HREF="sdlcdtrack.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_CDtrack</SPAN
></A
>)</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7604"
></A
><H2
>Description</H2
><P
>An <SPAN
CLASS="STRUCTNAME"
>SDL_CD</SPAN
> structure is returned by <A
HREF="sdlcdopen.html"
><TT
CLASS="FUNCTION"
>SDL_CDOpen</TT
></A
>. It represents an opened CDROM device and stores information on the layout of the tracks on the disc.</P
><P
>A frame is the base data unit of a CD. <TT
CLASS="LITERAL"
>CD_FPS</TT
> frames is equal to 1 second of music. SDL provides two macros for converting between time and frames: <TT
CLASS="LITERAL"
>FRAMES_TO_MSF(f, M,S,F)</TT
> and <TT
CLASS="LITERAL"
>MSF_TO_FRAMES</TT
>.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7614"
></A
><H2
>Examples</H2
><PRE
CLASS="PROGRAMLISTING"
>int min, sec, frame;
int frame_offset;

FRAMES_TO_MSF(cdrom-&#62;cur_frame, &#38;min, &#38;sec, &#38;frame);
printf("Current Position: %d minutes, %d seconds, %d frames\n", min, sec, frame);

frame_offset=MSF_TO_FRAMES(min, sec, frame);</PRE
></DIV
><DIV
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><A
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></A
><H2
>See Also</H2
><P
><A
HREF="sdlcdopen.html"
><TT
CLASS="FUNCTION"
>SDL_CDOpen</TT
></A
>,
<A
HREF="sdlcdtrack.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_CDtrack</SPAN
></A
></P
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