Perl write hashmap to file

However, the output file it produces is not in the human-readable format and may contain junk characters. Serialization : It is a process of writing an Object into a file along with its attributes and content. It internally converts the object into a stream of bytes. If we want to write a HashMap object to a plain text file, we need a simple and understandable code to write on the HashMap and then insert the Map into the Text File.

Skip to content. Change Language. Related Articles. Table of Contents. Improve Article. Below example shows that write content into the already created file. We have written content into the abc. This file contains the data. We have overwritten the data of the abc. Opening file abc. We have used the abc. Below is the data present in the abc. Source File name as abc. In the below example, we have created a file name as xyz. We have taken input from the user while writing data into the file.

Open and create file name as xyz. Perl write to file is used to write content into a file, we can copy content from one file and write into another text file. Nevertheless it might be useful to take a quick look how binary files can be handled in Perl.

On DOS and Windows systems these both change the filehandle to be in binary mode. On Unix, Linux, and OSX the binmode call or the :raw layer have no effect as those are the default anyway. Opening a binary file for writing Open for writing is the same, just use the greater-than sign instead of the less-than sign. When dealing with text-files we usually read line-by-line, or use the slurp mode to read all the lines into a single scalar variable.

Binary files have no notion of lines. There might be records or some other sections of the data, but not lines. Therefore we don't use the same readline operator as we used for the text files. Instead we use the read function that has a weird way of use. The function will try to read that many bytes from the file and put them in the scalar variable replacing whatever we had there. Optionally we can also supply a number to be "OFFSET", telling the read function where in scalar variable it should put the newly read bytes.

If we supply the current size of the scalar using the length function, then we append the newly read bytes to the end of the scalar variable. If we read that way repeatedly then we can read the whole content of the file into a single scalar variable. Of course assuming the file can fit in the free memory of our computer.

Then it saves the content to the second file.