Ruby File Open Block

With no associated block file open is.

Ruby file open block.

With no associated block file open is a synonym for new. With no associated block file open is a synonym for new. Always close a file that you open. Let s learn to do this ourselves.

If the optional code block is given it will be passed the opened file as an argument and the file object will automatically be closed when the block terminates. The syntax to open an existing file using ruby is as follows. The value of the block will be returned from file open. File openopens a new file if there is no associated block.

Open filename mode perm opt file block obj. Now let s try to read this file usr bin ruby afile file new input txt r if afile content afile sysread 20 puts content else puts unable to open file. For example following is the input text file this is a simple text file for testing purpose. How is this done.

A wonderful example is. Blocks are an excellent way to abstract pre and post processing. If the optional block is given it will be passed file as an argument and the file will automatically be closed when the block terminates. Ruby block patterns and how to implement file open managing resources with blocks.

In the case of a file open for writing this is very important and can actually prevent lost data. This method is similar to the file new method which is used to create a file object the only difference between the two being that the file open method can be associated with a block unlike the file new method.