CocoaDev

I had reason recently to want to get inside Safari’s favicon cache but I couldn’t find any information about how to do it. I came up with a method that could probably be greatly improved, especially since I was (am) utterly unfamiliar with the format that Apple stores them in. The result seems hackish to me but it works. I hope someone can use this and that many more can improve it or provide a better method.

// Assume path is a path to ~/Library/Safari/Icons/XX/YY/long-name.cache NSData *dat = [NSData dataWithContentsOfFile:path];

// Initialize and create a simple byte array unsigned char data[ [dat length] ]; [dat getBytes:data];

// Init variables. These could be moved up so I could use j when initializing // my byte array and make one less call, but I don’t think it is too costly. int i, j = [dat length], icostart; NSString *sitePath = [NSString string]; NSData *iconData = [NSData data];

// Iterate through the byte array for (i=0; i < j; i++) { if (data[i] == ‘h’ && data[i+1] == ‘t’ && data[i+2] == ‘t’) //found start of ico path (“http://…”) icostart = i; if (data[i] == ‘.’ && data[i+1] == ‘i’ && data[i+2] == ‘c’) //found ico path end (“… .ico”) { i += 4; // Move i to grab the rest of the path

	// I suppose I could use stringWithUTF8String but this method is left over from testing.
	sitePath = [NSString stringWithFormat:@"%s", 
		dat subdataWithRange:[[NSMakeRange(icostart, i - icostart)] bytes]];
	NSURL *url = [NSURL URLWithString:sitePath];  // A quick URL just to put the host into the icoPath
	sitePath = [url host];
}
if (data[i] == 'M' && data[i+1] == 'M' && data[i+2] == 0) //found start of icon
{
	iconData = [dat subdataWithRange:NSMakeRange(i, j - i)]; //Data goes to end of file.
	i = j; //Jump out
}	 }

There’s probably a lot that can be improved. This is tossed up immediately after testing and messing around with it so a good portion of it is left over from various debugging things (like stringWithFormat: instead of stringWithUTF8String: and setting i to j to jump out of the loop).

Note that the iconData is held in TIFF format, not .ico. Also, it appears to be scaled to 16x16. I know some favicons are larger, but Apple apparently scales them for the url field and bookmarks lists.

Any comments are greatly appreciated.