2024-09-25

6 min read

How to Copy Command Output Directly to Your Clipboard in Linux

You run a command that outputs a long string - maybe a hash, a file path, or a URL - and you need to paste it somewhere else. Instead of selecting and copying with your mouse, can you send it straight to the clipboard?

TL;DR

On Linux, install xclip and pipe command output to it: command | xclip -selection clipboard. On macOS, use the built-in pbcopy: command | pbcopy. For a shorter command, create an alias like alias clip='xclip -selection clipboard', then use command | clip. To paste from clipboard in the terminal, use xclip -selection clipboard -o or pbpaste on macOS.

Getting command output into your clipboard saves time and prevents copy-paste errors.

Let's say you generate an SSH key and want to copy the public key:

cat ~/.ssh/id_rsa.pub

Instead of selecting the output with your mouse, pipe it to the clipboard tool:

# Linux
cat ~/.ssh/id_rsa.pub | xclip -selection clipboard

# macOS
cat ~/.ssh/id_rsa.pub | pbcopy

Now the key is in your clipboard, ready to paste anywhere.

Installing xclip on Linux

Most Linux distributions don't have xclip installed by default:

# Ubuntu/Debian
sudo apt install xclip

# Fedora/RHEL
sudo dnf install xclip

# Arch
sudo pacman -S xclip

After installation, you can pipe to xclip.

Using xclip

The basic syntax:

command | xclip -selection clipboard

The -selection clipboard flag targets the system clipboard (the one used by Ctrl+C and Ctrl+V). Without it, xclip uses the X11 primary selection (middle-click paste).

Examples:

# Copy current directory path
pwd | xclip -selection clipboard

# Copy file contents
cat config.json | xclip -selection clipboard

# Copy command output
ls -la | xclip -selection clipboard

# Copy your IP address
ip addr show | grep "inet " | head -1 | awk '{print $2}' | xclip -selection clipboard

Creating a Shorter Alias

Typing -selection clipboard every time is tedious. Create an alias:

# Add to ~/.bashrc
alias clip='xclip -selection clipboard'

Reload your shell:

source ~/.bashrc

Now use it:

pwd | clip
echo "Hello" | clip
cat file.txt | clip

Using xsel as an Alternative

xsel is another clipboard tool with simpler syntax:

# Install xsel
sudo apt install xsel

# Copy to clipboard
command | xsel --clipboard

# Create alias
alias clip='xsel --clipboard'

Both xclip and xsel work well - choose whichever you prefer.

macOS: Using pbcopy and pbpaste

macOS includes pbcopy and pbpaste by default:

# Copy to clipboard
command | pbcopy

# Paste from clipboard
pbpaste

Examples:

# Copy file contents
cat ~/.ssh/id_rsa.pub | pbcopy

# Copy current directory
pwd | pbcopy

# Generate and copy a UUID
uuidgen | pbcopy

# Copy Git commit hash
git rev-parse HEAD | pbcopy

Pasting from Clipboard to Terminal

To paste clipboard contents into a file or use in a command:

Linux with xclip:

# Output clipboard contents
xclip -selection clipboard -o

# Save clipboard to file
xclip -selection clipboard -o > clipboard-contents.txt

# Use clipboard in a command
echo "The path is: $(xclip -selection clipboard -o)"

Linux with xsel:

xsel --clipboard --output

# Or shorter
xsel -ob

macOS:

# Output clipboard
pbpaste

# Save to file
pbpaste > file.txt

Practical Example: Copying SSH Keys

Add your SSH key to a remote server:

# Copy public key to clipboard
cat ~/.ssh/id_rsa.pub | clip

# Or on macOS
cat ~/.ssh/id_rsa.pub | pbcopy

Now paste it into the server's ~/.ssh/authorized_keys file via your web interface or terminal.

Share a complex command with a colleague:

# Copy the command to clipboard
echo 'docker run -d -p 8080:80 -v $(pwd):/usr/share/nginx/html nginx:latest' | clip

Now paste it into Slack, email, or a documentation file.

Practical Example: Working with APIs

Copy API responses:

# Get data from API and copy to clipboard
curl -s https://api.github.com/users/octocat | clip

# Copy just a specific field
curl -s https://api.github.com/users/octocat | jq -r '.name' | clip

Practical Example: Copy File Hashes

Generate and copy checksums:

# Copy SHA256 hash
sha256sum important-file.zip | awk '{print $1}' | clip

# Copy MD5 hash
md5sum file.txt | awk '{print $1}' | clip

Copying Multiple Items in Sequence

The clipboard holds only one item at a time. Each copy replaces the previous content:

# This copies "Hello"
echo "Hello" | clip

# This replaces it with "World"
echo "World" | clip

# Clipboard now contains only "World"

To accumulate multiple items, combine them first:

# Build a string with multiple values
{
    echo "Server Info:"
    echo "IP: $(hostname -I)"
    echo "Hostname: $(hostname)"
    echo "Uptime: $(uptime -p)"
} | clip

Clipboard in Scripts

Use clipboard in automation scripts:

#!/bin/bash

# Generate a password and copy it
PASSWORD=$(openssl rand -base64 32)
echo "$PASSWORD" | clip

echo "New password generated and copied to clipboard"
echo "Password will also be saved to passwords.txt"
echo "$PASSWORD" >> passwords.txt

Working with Large Output

Clipboard tools handle large content, but be aware of limitations:

# This might be too large for some clipboard managers
cat large-log-file.log | clip

# Better to copy a summary or filtered version
tail -100 large-log-file.log | clip

# Or search for specific patterns
grep "ERROR" large-log-file.log | clip

Clipboard Over SSH

When connected via SSH, copying to your local clipboard requires some setup:

Option 1: Use OSC 52 escape sequences (if your terminal supports it)

Some terminals can accept clipboard data via escape codes. Tools like clipboard or yank support this.

Option 2: Forward X11 and use xclip

# Connect with X11 forwarding
ssh -X user@server

# Now xclip on the server copies to your local clipboard
cat file.txt | xclip -selection clipboard

Option 3: Use tmux with clipboard support

Configure tmux to sync with your system clipboard.

Creating Helper Functions

Create useful clipboard functions:

# Add to ~/.bashrc

# Copy and paste shortcuts
alias c='xclip -selection clipboard'
alias v='xclip -selection clipboard -o'

# Copy current directory
alias cpwd='pwd | xclip -selection clipboard'

# Copy last command from history
alias clast='fc -ln -1 | xclip -selection clipboard'

After sourcing:

# Copy output
ls | c

# Paste clipboard
v

# Copy current directory
cpwd

Integrating with Git

Useful Git clipboard commands:

# Copy current branch name
git branch --show-current | clip

# Copy latest commit hash
git rev-parse HEAD | clip

# Copy remote URL
git remote get-url origin | clip

# Copy diff of last commit
git diff HEAD~1 | clip

Create Git aliases:

# Add to ~/.gitconfig
[alias]
    copy-branch = !git branch --show-current | xclip -selection clipboard
    copy-hash = !git rev-parse HEAD | xclip -selection clipboard

When Clipboard Tools Don't Work

If you're in a pure terminal environment without X11 (like a server with no GUI), xclip won't work. In these cases:

Save output to a file and transfer it
Use cat or less to view and manually copy
Set up X11 forwarding if connecting via SSH
Use terminal multiplexers with clipboard support

Clipboard Managers and History

Some clipboard managers keep a history of copied items. Tools like clipman, copyq, or diodon let you access previously copied content.

With these, you can:

Copy multiple items and paste them later
Search clipboard history
Organize frequently used snippets

Security Considerations

Be careful what you copy to the clipboard:

# Don't do this with sensitive data
cat private-key.pem | clip

# Clipboard might be logged by monitoring tools
echo "$SECRET_PASSWORD" | clip

For sensitive data:

Clear clipboard after use
Use secure password managers instead
Be aware of clipboard monitoring software

Using clipboard tools from the command line streamlines your workflow. Whether you're copying SSH keys, API responses, or file paths, piping to xclip, xsel, or pbcopy is faster and more accurate than manual selection.

Published: 2024-09-25|Last updated: 2024-09-25T09:00:00Z