fopen() always return NULL on iOS device-CodePudding

File exists in iOS bundle directory. fopen() always return NULL on iOS device, but OK on iOS sumulator, codes as below:

NSString *path = [NSBundle.mainBundle pathForResource:@"yuv420p_640x360" ofType:@"yuv"];
BOOL exists = [NSFileManager.defaultManager fileExistsAtPath:path];
NSLog(@"%d", exists); //prints "1"
const char *path2 = [path UTF8String];
FILE *fp = fopen(path2, "rb "); //fp is NULL

Environment: macOS 12.0.1, M1 MacBook Pro, iPadOS 15.0

CodePudding user response：

The iOS execution environment is sandboxed, and you can not open a file in the bundle with "writing" mode, since the files in the bundle can not be modified (try with just "r" for the mode).

CodePudding user response：

You cannot open any file in iOS. Apps are sandboxed in iOS i.e. An app can access only its directory and cannot access(read/write) any file outside its directory.