How to extract a marked part of file

In this example we will extract a part of file marked by __BEGIN__ and __END__ labels and save it into another file.

This is the original file:


The edit rules we add:

1. Find regular expression "(\A.*^[[:print:]]*__BEGIN__[[:print:]]*\r\n)(.*)(^[[:print:]]*__END__[[:print:]]*\r\n.*\z)":

By this regular expression we break a file into three parts: "Preceeding text", "Interesting part" and "The rest".

See also the Regular Expressions Syntax.

2. Select the current content of a scratch file (we will use it as a temporary buffer):


3. Put the "Interesting part" into scratch file:


4. Now let's prepare the new file name where the file will be saved. First, obtain the current file name:


5. Then compose the new file name using the current path name and extension:


6. Finally, save the scratch file with the new name that we have created:


Now the the Edit Rules window contains six rules as shown on the first plot.

Click "Apply all rules" to execute all rules and examine the Data View:

You can see the "Interesting part" moved to the scratch file and saved.

You can download the example files here: the original file, edit rules and the output file.


Please note that Mass File Editor becomes quite slow when opening a large files. It took several minutes to run this ruleset over a 15 Mb file: