osx - How do I use the `join` UNIX command? Nothing is ever output -

i feel i'm misunderstanding basic part of join command, because cannot work (running os x).

echo "testing" > 1.txt echo "text" > 2.txt join 1.txt 2.txt 

no output.

shouldn't have "testing text" result?

you don't have join because don't have 'matching fields'. need

echo "1 testing" > 1.txt echo "1 text" > 2.txt join 1.txt 2.txt 

to create 1 testing text because 'joins' (or matches) on 1