I am currently running a system simulation on multiple files.
I have a computer algorithm written in perl to run "system" simulations for all the files I need

What I am trying to do is put multiple files into one file, only problem is that its not doing exactly what I need it do

Example:

I am "cat txt0.txt txt1.txt txt2.txt txt3.txt > allfiles.txt"

I need it to read as

txt0.txt
txt1.txt
txt2.txt
txt3.txt

Instead its taking all the files and taking the information within each txt file and putting them all together. Info that looks like this


fdfasdfqwdefdfefdkfkkkkkkkkkkkkkkkfsdfasdxfewqfe..........

all clustered together

you get the picture ?

I am really confused how to get this to work, there are over 100 files that need to go into a single file.
That way when I run it through the perl algorithm I created, I can do it in one shot.

If I understand your problem correctly, it's that the source files have no trailing new line, so when they get catted it all ends up one one big line instead of each file's contents on their own.

In that case you can just do it in a for loop and manually stick a line break between them

It sounds like cat is working exactly as it should. It concatenates files.

I am guessing that you want allfiles.txt to contain the filenames, not the contents of those files. There are a number of ways to do that. Here is one:
Replace txt*.txt with the appropriate file specification for the file list you require.

This really is the QN: do you want the filenames listed into the new file or the contents (or both ??).
In any case, why bother? If you've already got a Perl program to process them, why not add some minimal code to handle multiple files?