Concatenating Files And Insert New Line In Between

Question

I have multiple files which I want to concat with cat. Let's say

File1.txt 
foo

File2.txt
bar

File3.txt
qux

I want to concat so that the final file looks like:

foo

bar

qux

Instead of this with usual cat File*.txt > finalfile.txt

foo
bar 
qux

What's the right way to do it?

Answer 1

This works in Bash:

for f in *.txt; do cat $f; echo; done

In contrast to answers with >> (append), the output of this command can be piped into other programs.

Examples:

• for f in File*.txt; do cat $f; echo; done > finalfile.txt
• (for ... done) > finalfile.txt (parens are optional)
• for ... done | less (piping into less)
• for ... done | head -n -1 (this strips off the trailing blank line)