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SDL_RWseek
Use this function (macro) to *call the seek function pointer in an SDL_RWops structure*.
Syntax
SDL_RWseek(ctx, offset, whence)
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(ctx)->seek(ctx, offset, whence)
Function Parameters
ctx |
*a pointer to an SDL_RWops structure* green |
offset |
*an offset in bytes, relative to '''whence''' location; can be negative* |
whence |
any of RW_SEEK_SET, RW_SEEK_CUR, RW_SEEK_END; see Remarks for details |
Return Value
Returns the final offset in the data source. ???
Code Examples
#include <stdio.h>
#include "SDL_rwops.h"
int main()
{
int length;
SDL_RWops *rw=SDL_RWFromFile("myfile.bin","rb");
if(rw==NULL)
{
fprintf(stderr,"Couldn't open myfile.bin\n");
return(1);
}
/* Seek to 0 bytes from the end of the file -- i.e. the exact end of file */
length=SDL_RWseek(rw,0,SEEK_END);
SDL_RWclose(rw);
if(length<0)
{
fprintf(stderr,"Could not seek inside myfile.bin\n");
return(2);
}
fprintf(stderr,"myfile.bin is %d bytes long\n",length);
return(0);
}
Remarks
Note: This is not a predefined function, just a macro that calls whatever seek function has been placed in the SDL_RWops structure.
whence may be any of the following values:
RW_SEEK_SET |
0 |
seek from the beginning of data |
RW_SEEK_CUR |
1 |
seek relative to current read point |
RW_SEEK_END |
2 |
seek relative to the end of data |
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Related Functions
SDL_RWclose (Macro) ???
SDL_RWread (Macro) ???
SDL_RWtell (Macro) ???
SDL_RWwrite (Macro) ???
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