Memory Mapped I/O Example

char *ShareMalloc( int size )

{

int fd;

char *returnPtr;

if( (fd = open( "/tmp/mmap", O_CREAT | O_RDWR, 0666 )) < 0 )

Abort( "Failure on open" );

if( lseek( fd, size-1, SEEK_SET ) == -1 )

Abort( "Failure on lseek" );

if( write( fd, "", 1 ) != 1 )

Abort( "Failure on write" );

if( (returnPtr = (char *) mmap(0, size, PROT_READ|PROT_WRITE,

MAP_SHARED, fd, 0 )) == (caddr_t) -1 )

Abort( "Failure on mmap" );

return( returnPtr );

}

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