So I was testing out a write file function I wrote after adapting some code from OSTEP. This happened and I was confused. So the first time it wouldn't print the last character into the file so I fixed some stuff and this happened.
@AJDevelopment Wait, when you call write(), you set the length parameter to 13. It should be the size of the string (in the example in the PDF, "hello world\n" has 13 characters)