moveItemAtPath可在iPad上使用，但不能在Simulator上使用？

Question

I am using moveItemAtPath call to change a file extension from .PDF to .pdf (just lowercasing it). It fails on the simulator as shown below, but works fine on the device. Could it be some sort of permissions problem?

lowerPDF=[upperPDF stringByReplacingOccurrencesOfString:@".PDF" withString:@".pdf"];
NSLog(@"Lowercasing filename %@ to %@",upperPDF,lowerPDF);
if (![fm moveItemAtPath:upperPDF toPath:lowerPDF error:&error]) 
    NSLog(@"RENAME error %@",[error localizedDescription]);

NextPage[13625:207] Lowercasing filename /Users/scott/Library/Application Support/iPhone Simulator/4.2/Applications/7D38A00A-3990-441C-96C5-DD56EC3B6922/Documents/What a Difference a Day made 24010812.PDF to /Users/scott/Library/Application Support/iPhone Simulator/4.2/Applications/7D38A00A-3990-441C-96C5-DD56EC3B6922/Documents/What a Difference a Day made 24010812.pdf
NextPage[13625:207] RENAME error The operation couldn’t be completed. (Cocoa error 512.)

Thanks,

//Scott

Answer 1

The filesystem on a Mac is normally case-insensitive, while the filesystem on the device is case-sensitive. So on the device, "foo.PDF" and "foo.pdf" are two different files, while on the Mac's filesystem used by the simulator they are the same.