Written 30 Aug 2026. This is a how-to, not a product card.

Join columns side by side

After SSH works, join columns side by side with paste so two lists become one line each. You don't need a file manager for this.

Change characters cleaned mixed lines. Pull one column kept fruit and color apart. Tonight you join columns side by side so two lists become one line each. paste does that. Fruit can sit next to color. You are still only looking. The computer does not need a desktop, a file manager, or a new mini PC for this one job.

Skip until SSH already works

SSH from the couch should already get you a prompt. If a column pulled is what you want, that is pull one column. If files matched on a shared field are what you want, that is match files on a shared field. join is a different tool. Skip this whole note if you only need a house share other computers browse. That is a folder the house can open.

What this is

paste joins columns side by side. You type paste, then two files. -d is delimiter: the character that sits between columns. Default join is tab. Comma is optional tonight. It prints joined lines. It does not rewrite the files unless you ask it to.

It is not join. Join matches files on a shared field. Paste joins columns side by side without matching keys. It is not cut. Cut pulls one column out. It is not nl. Nl numbers lines.

Join columns from practice files

SSH into the computer.

Make two tiny files in home:

printf 'apple\nbanana\npear\n' > ~/fruit.txt

printf 'red\nyellow\ngreen\n' > ~/color.txt

That save is save output to a file. Peek first:

cat ~/fruit.txt

You want apple, then banana, then pear. Peek color too:

cat ~/color.txt

Join them side by side:

paste ~/fruit.txt ~/color.txt

You want apple next to red, banana next to yellow, pear next to green. That is enough for tonight. Practice only in home.

Debian and Ubuntu usually already have paste. Don't make apt the job. If paste is missing:

sudo apt install coreutils

Then stop. That install is not the lesson.

When you are done, throw the practice files away. Careful delete only. That is delete a file carefully. Skip rm -rf.

rm ~/fruit.txt ~/color.txt

Useful extras, still looking only

Optional: comma between columns:

paste -d, ~/fruit.txt ~/color.txt

Optional: a pipe character:

paste -d '|' ~/fruit.txt ~/color.txt

Don't make -d required. You can stay on the default tab.

What this is not

This is not join. That is match files on a shared field. It is not cut. That is pull one column. It is not tr. That is change characters. It is not nl. That is number lines. It is not a house share. That is a folder the house can open. It is not opening SSH to the internet. That is keep the computer on the house network. Don't forward port 22.

What next

Need one column pulled? Pull one column. Need files matched on a key? Match files on a shared field. Need characters cleaned? Change characters. Need lines numbered? Number lines. Keep SSH on the house network: keep the computer on the house network. Don't forward port 22.

Skip

• Skip if SSH still fails. Finish SSH from the couch first.
• Skip join, cut, tr, and nl as tonight's job. Those pages already exist.
• Skip paste into rm. Paste prints. Don't mix delete into this drill.
• Skip files under /etc, SSH folders, or paths you don't own. Practice only in home.
• Skip rm -rf. Careful delete only: delete a file carefully.
• Skip opening SSH to the internet so you can do this from a coffee shop. That is keep the computer on the house network. Don't forward port 22.