uticon.m

#import <Foundation/Foundation.h>
#import <AppKit/AppKit.h>
#import <ScreenSaver/ScreenSaver.h>

// Returns the file path of an unused temporary file
// (e.g. /var/folders/NU/.../1023.tmp)
NSString *getTempFilePath (NSString *extension) {
	NSString *tempDirectory = NSTemporaryDirectory();
	NSFileManager *fileManager = [NSFileManager defaultManager];
	NSString *tempFilePath;
	BOOL pathExists = YES;
	while (pathExists == YES) {
		// creating a random integer value between 1000 and 9999 with
		// a convenient function found in the ScreenSaver framework
		int randnum = SSRandomIntBetween(1000, 9999);
		// e.g. /TemporaryDirectory/8765.tmp
		tempFilePath = [NSString stringWithFormat:@"%@%d.%@", tempDirectory, randnum, extension];
		if ([fileManager fileExistsAtPath:tempFilePath] == NO) {
			pathExists = NO;
		}
	}
	// tempFilePath is an autoreleased object (created with [NSSString stringWithFormat])
	return tempFilePath;
}

// The main function called when the script is opened
int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
	// we expect exactly two arguments, the Uniform Type Identifier (UTI)
	// and the name of the script itself
	if (argc != 2) {
		printf("Usage: uticon [Uniform Type Identifier (e.g. public.pdf]\n");
		return 1;
	}
	// getting the icon (NSImage) for the given UTI
	NSArray *args = [[NSProcessInfo processInfo] arguments];
	NSString *UTI = [args objectAtIndex:1];
	NSWorkspace *workspace = [NSWorkspace sharedWorkspace];
	NSImage *icon = [workspace iconForFileType:UTI];
	// converting to TIFF data and writing it to a temporary file
	NSData *tiffData = [icon TIFFRepresentation];
	NSString *tiffFilePath = getTempFilePath(@"tiff");
	BOOL writeSuccess = [tiffData writeToFile:tiffFilePath atomically:NO];
	if (writeSuccess == NO) {
		printf("Could not write TIFF data to temporary file at: %s\n", [tiffFilePath UTF8String]);
		return 1;
	}
	// converting the TIFF to an ICNS file using the command line tool tiff2icns
	NSString *iconFilePath = getTempFilePath(@"icns");
	NSTask *shellCommand = [[NSTask alloc] init];
	[shellCommand setLaunchPath:@"/usr/bin/tiff2icns"];
	[shellCommand setArguments:[NSArray arrayWithObjects:tiffFilePath, iconFilePath, nil]];
	[shellCommand launch];
	[shellCommand waitUntilExit];
	[shellCommand release];
	// removing the temporary TIFF file
	NSFileManager *fileManager = [NSFileManager defaultManager];
	[fileManager removeItemAtPath:tiffFilePath error:NULL];
	// returning the ICNS file path
	printf("%s\n", [iconFilePath UTF8String]);
    [pool drain];
    return 0;
}