📋 cb

Universal command-line clipboard with automatic copy and paste detection. Eg, cb|sort|cb.

Purpose

cb is a clipboard for working between graphical and command-line interfaces (GUIs and CLIs). The clipboard is a surprisingly convenient integration between the two and doesn't use temporary files. cb automatically performs a copy or a paste based on the context.

Why you don't need cb

If any of the following are true, you do not need cb:

• You use GUIs exclusively.
• You use CLIs exclusively.
• You can use the system equivalent copy-and-paste CLIs directly. Eg, XSel or pbcopy / pbpaste.
• You prefer using temporary files when working across GUIs and CLIs.

All cb provides is a consistent interface across operating systems. Any clipboard CLI will do. What's important is how you use the tool.

Usage

Supply standard input to copy:

$ echo abc|cb

Supply no input to paste:

$ cb
abc

Both copy and paste can appear in the same command:

$ curl "$(cb)"|cb

Contents on the clipboard can be used bidirectionally with other GUIs like graphical text editors or web browsers using the usual shortcut (control-c/v or command-c/v).

Installation

# Download the script to ~/bin/cb.
curl https://raw.githubusercontent.com/niedzielski/clipboard/main/cb -o ~/bin/cb &&

# Make the script executable.
chmod +x ~/bin/cb

cb also supports sourcing in Almquist-like shells like . cb or source ./cb.

The heart of cb is tiny so edit it however you like and discard the rest!

Dependencies

cb requires the following dependencies to be installed:

• Linux: xclip on X (eg, sudo apt install xclip) and wl-clipboard on Wayland (sudo apt install wl-clipboard).
• macOS: none (pbcopy / pbpaste are installed by default).
• Windows: CygUtils (install putclip / getclip via Cygwin GUI).

If in doubt, it's simplest to just try executing cb.

Troubleshooting

Is ~/bin in the PATH environment variable? grep --only-matching ~/bin <<< "$PATH" should report a match. If not, add it like PATH="$PATH":~/bin.

Examples

All of these examples appear trivial because copy-and-paste is ubiquitous. The intent is to demonstrate the understated usefulness of the system clipboard for CLI-GUI integration. You can work seamlessly across GUIs and CLIs with it.

• Sort clipboard lines: cb|sort|cb.

  Expand for detail…

  $ # Simulate copying some lines of text from another program with control or command-C.
  
  $ printf 'c\nb\na'|cb
  
  $ cb
  c
  b
  a
  
  $ # Sort the clipboard's contents by line.
  
  $ cb|sort|cb
  
  $ # Simulate pasting the text back to another program with control or command-V.
  
  $ cb
  a
  b
  c

• Count the number of bytes, characters, and lines on the clipboard: cb|wc --bytes --chars --lines.

  Expand for detail…

  $ # Simulate copying text from another program with control or command-C.
  
  $ echo abc|cb
  
  $ cb|wc --bytes --chars --lines
        1       4       4

• Replace single quotes with double quotes on the clipboard: cb|sed s%\'%\"%g|cb.

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  $ # Simulate copying text from another program with control or command-C.
  
  $ cb <<<\'abc\'
  
  $ cb|sed s%\'%\"%g|cb
  
  $ # Simulate pasting the text back to another program with control or command-V.
  
  $ cb
  "abc"

• Diff the clipboard with a file: diff <(cb) right-hand-side.text. Works with diff GUIs too: meld <(cb) right-hand-side.text.

  Expand for detail…

  $ # Simulate copying some lines of text from another program with control or command-C.
  
  $ cb << 'eof'
  a
  b
  eof
  
  $ # Simulate a previously saved reference.
  
  $ cat << 'eof' > right-hand-side.text
  a
  b
  c
  eof
  
  $ # Diff the contents of the clipboard with the reference.
  
  $ diff <(cb) right-hand-side.text
  2a3
  > c
  
  $ # View the same diff in Meld, a graphical diffing program.
  
  $ meld <(cb) right-hand-side.text

  

• Download a file from the URL on the clipboard: wget "$(cb)".

• Download a video from the YouTube URL on the clipboard: youtube-dl "$(cb)".

  Expand for detail…

  $ # Simulate copying a URL from a browser address bar with control or command-C.
  
  $ echo 'https://www.youtube.com/watch?v=92c8vW-AzAc'|cb
  
  $ # Download the address from the clipboard URL.
  
  $ youtube-dl "$(cb)"
  [youtube] 92c8vW-AzAc: Downloading webpage
  WARNING: Requested formats are incompatible for merge and will be merged into mkv.
  [download] Destination: Fritz roars-92c8vW-AzAc.f137.mp4
  [download] 100% of 5.07MiB in 01:37
  [download] Destination: Fritz roars-92c8vW-AzAc.f251.webm
  [download] 100% of 175.94KiB in 00:02
  [ffmpeg] Merging formats into "Fritz roars-92c8vW-AzAc.mkv"
  Deleting original file Fritz roars-92c8vW-AzAc.f137.mp4 (pass -k to keep)
  Deleting original file Fritz roars-92c8vW-AzAc.f251.webm (pass -k to keep)
  
  $ ls Fritz\ roars-92c8vW-AzAc.mkv
  'Fritz roars-92c8vW-AzAc.mkv'

• Copy the version of Chromium to the clipboard: chromium --version|cb.

  Expand for detail…

  $ # Copy the version of Chromium installed into the clipboard.
  
  $ chromium --version|cb
  
  $ # Simulate pasting the version into another program with control or command-V.
  
  $ cb
  Chromium 97.0.4692.99 built on Debian bookworm/sid, running on Debian bookworm/sid

• Copy 10k numbered lines to the clipboard: for ((i=0; i < 10000; i++)); do echo $i; done|cb.

  Expand for detail…

  $ # Copy numbered lines from 0 to 10000 to the clipboard.
  
  $ for ((i=0; i < 10000; i++)); do echo $i; done|cb
  
  $ # Simulate pasting the text into another program with control or command-V.
  
  $ cb|head
  0
  1
  2
  3
  4
  5
  6
  7
  8
  9

• Replace newlines on the clipboard with commas: cb|node --input-type=module --eval 'import fs from "fs/promises"; const text = await fs.readFile("/dev/stdin", "utf-8"); console.log(text.split("\n").join())'|cb.

  Expand for detail…

  $ # Simulate copying text delimited by newlines from another program with control or command-C.
  
  $ echo -ne 'a\nb\nc'|cb
  
  $ cb|node --input-type=module --eval 'import fs from "fs/promises"; const text = await fs.readFile("/dev/stdin", "utf-8"); console.log(text.split("\n").join())'|cb
  
  $ # Simulate pasting the CSV back to another program with control or command-V.
  
  $ cb
  a,b,c

• Pretty print JSON: cb|node -pe 'JSON.stringify(JSON.parse(require("fs").readFileSync(0, "utf-8")), null, 2)'|cb.

  Expand for detail…

  $ # Simulate copying a blob of JSON from another program with control or command-C.
  
  $ cb <<<'{"a":1,"b":2,"c":3}'
  
  $ cb|node -pe 'JSON.stringify(JSON.parse(require("fs").readFileSync(0, "utf-8")), null, 2)'|cb
  
  $ # Simulate pasting the JSON back to another program with control or command-V.
  
  $ cb
  {
    "a": 1,
    "b": 2,
    "c": 3
  }

• Test if the random patch you found online and copied to your clipboard applies to your code: git apply --check <(cb).

• Dump the HEAD revision of a file to the clipboard: git show HEAD:readme.md|cb.

• Reverse clipboard line order: cb|tac|cb.

• Copy an image to the clipboard: cb < banana.png.

• Wrap clipboard text at 72 characters: cb|fold --spaces --width=72|sed 's% \+$%%'|cb.

• Find songs, shuffle them, and copy them to the clipboard: find -iname \*.flac -printf %f\\n|shuf|cb.

• Copy the absolute path of a filename: realpath --canonicalize-missing --no-symlinks "$(cb)"|cb.

• Voice the clipboard: cb|espeak.

• Truncate the clipboard: cb|tail|cb.

• Save the clipboard to a transient file: t="$(mktemp)" && cb >| "$t" && echo "$t".

• Edit the clipboard contents in a temporary buffer cb|vim -.

• Compare Gzip and Brotli compressions of the clipboard: cb|gzip --best|wc --bytes && cb|brotli --best|wc --bytes.

• Copy the most recent photo taken on an Android device to the clipboard: adb exec-out 'cat "$(ls -c1 /sdcard/DCIM/Camera/IMG*.jpg|tail -n1)"'|cb.

• Clear the clipboard: cb < /dev/null.

License (Public Domain)

All code in this repository is public domain and may be used without limitation.