Handling CR line endings in Lua

Question

I'm trying to read a file with CR line endings using the file:read method which seems to be acting up for some reason. The file contents look like this:

ABCDEFGH
12345
##
6789

I want it to behave consistently with all types of line endings. Every time I try to read the file, it returns the last line in the file concatenated with the any trailing characters from the previous lines that have a greater position than the position of the last character in the last line. Here's what I mean:

> file=io.open("test.lua", "rb")
> function re_read(openFile)
     openFile:seek("set");
     return openFile:read("*a");
  end
> =re_read(file) -- With CR
67895FGH

> =re_read(file) -- With CRLF
ABCDEFGH
12345
##
6789

> =re_read(file) -- with LF
ABCDEFGH
12345
##
6789

>

As you can see, the string being returned is the last string plus 5 in the previous line and plus FGH from the first line. Any lines shorter than the last line are skipped.

My goal is to use the file:line() method to read the file line by line. My hope is that if a 'fix' for file:read is found then it can be applied to file:lines().

Handling CR line endings in Lua

2 Answers