Move lines from one .txt file to another

Question

I am trying to move certain lines from one .txt file to another. These lines all follow a certain pattern. I have been looking at using the find command in a batch file, but this does not delete the line from the original file.

For example:

find \i pattern "d:\example1.txt" >> "d:\example2.txt"

Is there any way to achieve this?

Thanks in advance.

Answer 1

How about creating two files, then replacing the original?

find \i pattern "d:\example1.txt" >> "d:\example2.txt"
find \i antipattern "d:\example1.txt" >> "d:\example3.txt"
del example1.txt
ren example3.txt example1.txt

Deleting lines from files is hard. Typically, even in a genuine programming environment, you'd be using an extra file here.

Here's a slightly different implementation:

ren example1.txt source.txt
find \i pattern "d:\source.txt" >> "d:\example2.txt"
find \i antipattern "d:\source.txt" >> "d:\example1.txt"
del source.txt

Answer 2

Using findstr you can print lines that don't match, too. So you can do it in several steps, psudocoded like this:

• findstr pattern input > output
• findstr /v pattern input > input-inverse
• move /y input-inverse input

This should leave you with all lines matching pattern in output, and an input without those lines.

EDIT: Made the last step use move with an option to overwrite, so no need to remove the input before. I guess I (being mainly a Linux person) think of "rename" and "move" as the same thing, and took that overwrite for granted. So, thanks for the heads-up.

Answer 3

If you can use external programs, one way would be using awk or sed.

Awk example:

awk /pattern/ { print }

Sed example:

sed '/inverse_pattern/ d' //Deletes lines which do not match

Answer 4

Use Sed.