Question

I have this file which I need to read the first bytes to check the information.
I don’t need to load the whole file, only the beginning..
The code in C is, more or less, what follows. It is a big code, so I just wrote the basic functionality here.

Now I want to make it 100% Objective-C, but I cannot find a way to do it properly.

FILE *f;
char *buf;

f = fopen ("/Users/foo/Desktop/theFile.fil", "rb");

if(f) {
fseek(f , 0 , SEEK_END);
size = ftell(f);
rewind (f);
buf = (char*) malloc (sizeof(char)*size);
switch( ntohl(*(uint32 *)buf) ) {
    case 0x28BA61CE:
    case 0x28BA4E50:
        NSLog(@"Message");
    break;
}

fclose(f);
free (buf);

The most close I got to this is what follows:

NSData *test = [[NSData alloc] initWithContentsOfFile:filePath];

This gets me all the binary, but anyway, I got stuck. Better try to start all over..

Any help appreciated!

Answer 1

Well.. I sorted that out.. And did what follows.

Cheers and thanks for the help!

NSString *filePath = [[NSString alloc] initWithFormat:@"/Users/foo/Desktop/theFile.fil"];

NSData *data = [NSData dataWithContentsOfFile:filePath];
NSUInteger len = [data length];
Byte *byteData = (Byte*)malloc(len);
memcpy(byteData, [data bytes], len);

NSNumber *size = [[NSNumber alloc] initWithUnsignedLong:len/2^20];

NSLog(@"%@", size);

switch( ntohl(*(uint32 *)byteData) ) {
    case 0x28BA61CE:
    case 0x28BA4E50:
        NSLog(@"Message");
    break;
}
[size release];
[filePath release];