Question

I’m trying to concatenate every file in a folder in lua to compile a bunch of logs into one master log and send it off to someone. I’m using the ifs library to iterate through every file in a directory, then reading it all in and trying to append it to the master file.

for name in lfs.dir("logs") do
    if(name ~= "." and name ~= "..") then
     local path = "logs/"..name
     print (path)
     local file=io.open(path,"R")
     print "2"
     local content = io.read("*all")
     print "3"
     io.close(file)

     local f=io.open("log.csv","A")
     file:write(content)
     io.close(f)    
    end
end 

There are two issues.
The ifs library returns “.” and “..” before the other file names [is there a better way to ignore these than an if statement?]
using the bit I found here: How to load all files from a directory?

The important issue is that my command prompt keeps crashing when I test the file. It prints the path (a good one), then it crashes before getting to the “2” and I’m not sure why. The file exists and I can manipulate it by adding lines to it in another function.

Any help would be greatly appreciated.

Answer 1

To avoid checking for "." and ".." you should use lfs.attributes and its mode field to see if each item is a file or directory (or something else).

Instead of io.read you probably want file:read — this might be the cause of your “crash.”

I suggest you use "r" and "a+" for the io.open mode arguments.

Oh, and use f:write to write content