0

How can I get input from the console in Objective C? My concern is to avoid the possibility of buffer overflows, which is why I want to steer clear of gets() and scanf()/sscanf(). From searching StackOverflow, that's all I've been seeing. Is scanf() more secure in Objective C to the extent that I wouldn't have to worry?

Just recently, I found this example: I like it; but is there already a class for such?

printf("What is your name?"); NSFileHandle *input = [NSFileHandle fileHandleWithStandardInput]; NSData *inputData = [NSData dataWithData:[input availableData]]; NSString *inputString = [[NSString alloc] initWithData:inputData encoding:NSUTF8StringEncoding]; inputString = [inputString stringByTrimmingCharactersInSet: [NSCharacterSet whitespaceAndNewlineCharacterSet]]; printf("Hello %s.n",[inputString UTF8String]);

Improve this question
1
  • Write an iOS app in Objective-C with a UITextField and take input from that perhaps? :D Commented Feb 23, 2014 at 2:49

1 Answer 1

Reset to default
1

The standard C I/O functions can be used, as you indicate. They are not more secure just because you are using Objective-C. To avoid buffer overflow issues use fgets rather and gets. Note you will be reading a C-style string and will need to convert it if you need an NSString.

At the Cocoa level you can use NSFileHandle as you show. Note that availableData returns all the available data not the next line, but as the console device is usually set to line mode what will be returned is the next line provided the user has not typed ahead.

At a lower level you can look at read.

HTH

Improve this answer
Sign up to request clarification or add additional context in comments.

1 Comment

fgetln() is also worth a look if you want line-oriented input. If you want to allow the user to edit the line as they type you should look at GNU readline or BSD readline.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.