Is there anyway to do Files Handling in Objective-C? I am just trying to do simple read and write and can use 'c' but i am force to use Objective-C classes for that :@. I am looking into NSInputStream, but its going over my head. Is there any tutor开发者_开发问答ial which explains how to use NSInputStream?
I had trouble with basic file i/o when I first hit it in Obj-C as well. I ended up using NSFileHandle to get C style access to my file. Here's a basic example:
// note: myFilename is an NSString containing the full path to the file
// create the file
NSFileManager *fManager = [[NSFileManager alloc] init];
if ([fManager createFileAtPath:myFilename contents:nil attributes:nil] != YES) {
NSLog(@"Failed to create file: %@", myFilename);
}
[fManager release]; fManager = nil;
// open the file for updating
NSFileHandle *myFile = [NSFileHandle fileHandleForUpdatingAtPath:myFilename];
if (myFile == nil) {
NSLog(@"Failed to open file for updating: %@", myFilename);
}
// truncate the file so it is guaranteed to be empty
[myFile truncateFileAtOffset:0];
// note: rawData is an NSData object
// write data to a file
[myFile writeData:rawData];
// close the file handle
[myFile closeFile]; myFile = nil;
If all you need to do is really simple I/O, you can just tell an object to initialize itself from, or write itself to, a filesystem path or URL. This works with several Foundation classes, including NSString, NSData, NSArray, and NSDictionary among others.
Try starting out by looking at the following two NSString methods:
- initWithContentsOfFile:encoding:error:
- writeToFile:atomically:encoding:error:
I find apple's guides short and to the point. http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/Streams/Articles/ReadingInputStreams.html
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