For the More Curious: Reading and Writing to the Filesystem

In addition to archiving and NSData’s binary read and write methods, there are a few more methods for transferring data to and from the filesystem. One of them, Core Data, is coming up in Chapter 16. A couple of others are worth mentioning here.

You have access to the standard file I/O functions from the C library. These functions look like this:

F​I​L​E​ ​*​i​n​F​i​l​e​ ​=​ ​f​o​p​e​n​(​"​t​e​x​t​f​i​l​e​"​,​ ​"​r​t​"​)​;​ c​h​a​r​ ​*​b​u​f​f​e​r​ ​=​ ​m​a​l​l​o​c​(​s​o​m​e​S​i​z​e​)​;​ f​r​e​a​d​(​b​u​f​f​e​r​,​ ​b​y​t​e​C​o​u​n​t​,​ ​1​,​ ​i​n​F​i​l​e​)​;​ F​I​L​E​ ​*​o​u​t​F​i​l​e​ ​=​ ​f​o​p​e​n​(​"​b​i​n​a​r​y​f​i​l​e​"​,​ ​"​w​"​)​;​ f​w​r​i​t​e​(​b​u​f​f​e​r​,​ ​b​y​t​e​C​o​u​n​t​,​ ...

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