Ruby File Open Block

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.

Ruby file open block.

Blocks are an excellent way to abstract pre and post processing. File openopens a new file if there is no associated block. With no associated block file open is. Let s learn to do this ourselves.

Ruby block patterns and how to implement file open managing resources with blocks. A wonderful example is. You can open the file in any of the modes when using the method sysread. How is this done.

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. With no associated block file open is a synonym for new. The syntax to open an existing file using ruby is as follows. The value of the block will be returned from file open.

For example following is the input text file this is a simple text file for testing purpose. 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. Always close a file that you open. 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.

In the case of a file open for writing this is very important and can actually prevent lost data. With no associated block file open is a synonym for new.