CODEWITHSUNDEEP
ciommap
Dooderino
Dooderino

Reputation: 91

Map a file and get byte value

I need to map a file and then get it's byte value (from the mapped region).

I've map the file, like so:

void* kd_test_mmapw( int d, int size )
{
    void *a = NULL;
    a = mmap( NULL, size, PROT_READ, MAP_SHARED, d, 0 );
    if( a == MAP_FAILED )
    {
        perror( "mmap failed" );
        abort();
    }
    return a;
}

But I have no idea how to get the byte value

Upvotes: 0

Views: 1574

Answers (1)

GHugo
GHugo

Reputation: 2654

a is a pointer to the first byte of you mapped region. You can consider your pointer as a pointer to an array of bytes.

If you want to access the 1234 bytes, just use:

char *asChar = (char*)a;
char myByte = asChar[1233];

Upvotes: 2

Related Questions