How I Use CLI2ELI to Streamline Text Transformation in Emacs

I frequently work with escaped SQL strings from API logs and debugging sessions. The typical workflow involved copying the string, finding an online unescaper, pasting, copying the result, then finding a SQL formatter, pasting again… you get the idea. Too many context switches.

I wanted something like M-| (shell-command-on-region) but with predefined commands I could invoke by name. CLI2ELI made this trivial.

The Problem

When debugging data pipelines, I often encounter JSON-escaped SQL like this:

"SELECT date_trunc('month', at_timezone(kpis.\"time\",'UTC')) AS time\nFROM \"prod_analytics\".\"public\".\"machines_kpis_30_min\" kpis\nWHERE kpis.\"machine_id\" IN (UUID '3ee28f49-6792-48f9-9ca9-ba6f86d73753')"

I need to:

1. Unescape the JSON string
2. Format the SQL for readability

With M-|, I’d have to type jq -r '.' | sqlfmt - every time. Not hard, but tedious when you do it dozens of times a day.

The Solution: CLI2ELI with stdin Support

CLI2ELI wraps CLI tools as named Emacs commands. With the new stdin property, I can pipe buffer or region content directly to commands.

Here’s my configuration in cli-transform.json:

{
  "tool": "cli-transform",
  "cwd": "default",
  "commands": [
    {
      "name": "unescape SQL",
      "description": "Unescape JSON-escaped SQL string",
      "command": "jq -r '.'",
      "stdin": "region"
    },
    {
      "name": "format SQL",
      "description": "Format SQL using sqlfmt",
      "command": "sqlfmt -",
      "stdin": "region"
    },
    {
      "name": "unescape and format SQL",
      "description": "Unescape and format in one step",
      "command": "jq -r '.' | sqlfmt -",
      "stdin": "region"
    }
  ]
}

That’s it. Three lines per command.

Usage

1. Select the escaped SQL string
2. M-x cli-transform-unescape-and-format-sql
3. Formatted SQL appears in the output buffer

The output buffer shows the command in the header line, making it clear what ran. Copy the result and move on.

The stdin Property

The stdin field accepts two values:

• "region": Selected text, or entire buffer if no selection
• "buffer": Always uses entire buffer content

This covers most text transformation use cases.

More Examples

Once you have the pattern, adding more transforms is trivial:

{
  "name": "format JSON",
  "command": "jq '.'",
  "stdin": "region"
},
{
  "name": "minify JSON",
  "command": "jq -c '.'",
  "stdin": "region"
},
{
  "name": "base64 decode",
  "command": "base64 -d",
  "stdin": "region"
},
{
  "name": "url decode",
  "command": "python3 -c 'import sys,urllib.parse;print(urllib.parse.unquote(sys.stdin.read()))'",
  "stdin": "region"
}

Any CLI tool that reads from stdin works.

Why CLI2ELI?

Named commands: M-x cli-transform-format-json is discoverable and memorable. No need to recall exact command syntax.

JSON configuration: No Elisp required. Adding a new transform takes 30 seconds. More importantly, JSON is trivial for AI coding agents to generate. Ask Claude or Copilot to “add a command that converts CSV to JSON” and it can produce the correct JSON config immediately. Try asking it to write the equivalent Elisp—much harder to get right.

Composable: Pipe multiple tools together in the command field. Unix philosophy meets Emacs.

Consistent interface: All transforms work the same way—select text, run command, get output.

Getting Started

1. Install CLI2ELI from GitHub
2. Create a JSON config file with your transforms
3. Load it: (cli2eli-load-tool "~/path/to/config.json")
4. Start transforming

The barrier to entry is low. Define a command in JSON, reload, use it. When you find yourself typing the same shell pipeline repeatedly, wrap it in CLI2ELI.