Do-Nothing Scripting

Inspired by Dan Slimmon's do-nothing scripting pattern, this skill converts a command sequence — from any source — into a do-nothing bash script: a runnable procedure that walks an operator through each step manually, while making each step trivially replaceable with real automation later.

Role

You are an expert in shell scripting, automation strategy, and the do-nothing scripting pattern. You understand:

• How to read asciinema v3 .cast files and extract the sequence of commands a user ran
• How to parse plain text files and shell history output to extract command lists
• How to interview a user to elicit the steps of a manual procedure
• How to identify logical groupings of commands into named steps
• How to write idiomatic, safe bash following modern best practices
• How to structure a do-nothing script so each step can be independently automated over time
• How to surface context variables (usernames, paths, URLs) that a step depends on

Input Modes

This skill accepts four input modes. Choose the mode that matches what the user provides:

Do-Nothing Scripting Principles

A do-nothing script:

• Does not execute the steps — it prints instructions and waits for the operator to act
• Encapsulates each step in a function so any step can later be replaced with real automation without changing the rest of the script
• Collects context (dynamic values like usernames or ticket IDs) by prompting the operator once and threading the values through subsequent steps
• Lowers the activation energy for full automation by making the gap between "manual" and "automated" a single function rewrite

Workflow

1. Determine the input source — Ask the user which input mode applies if it is not already clear:

   • cast: "Do you have an asciinema .cast file? If so, what is the path?"
   • text: "Do you have a text file listing the commands? If so, what is the path?"
   • history: "Would you like to use your recent shell history? Run: history <N> > /tmp/history.txt"
   • interview: "I don't see an input file. Let's build the script together — what is the first step in your procedure?" Continue asking "What is the next step?" until the user says there are no more steps. Record each step description as a command line in /tmp/<name>_steps.txt, then proceed as for the text mode.

2. Extract the command list — Use references/extract_commands.py to pull the command sequence. The script auto-detects the format, or you can override with --format=:

   # auto-detect (cast, history, or text)
   python3 skills/do-nothing-scripting/references/extract_commands.py ./tmp/<name>.cast
   
   # explicit formats
   python3 skills/do-nothing-scripting/references/extract_commands.py --format=cast    ./tmp/<name>.cast
   python3 skills/do-nothing-scripting/references/extract_commands.py --format=history ./tmp/history.txt
   python3 skills/do-nothing-scripting/references/extract_commands.py --format=text    ./tmp/steps.txt
   

   The script prints each detected command prefixed with its sequence number. Review the output and discard noise (shell prompts, clear, incidental cd calls that are part of navigation rather than procedure).

   Capturing history directly:

   history 20 > /tmp/history.txt
   python3 skills/do-nothing-scripting/references/extract_commands.py --format=history /tmp/history.txt
   

3. Group commands into logical steps — Examine the command list and cluster related commands into named steps. Good step names are verb phrases that describe what a human does, not what the computer does:

   • create_feature_branch (not git_checkout)
   • update_config_file (not sed)
   • wait_for_pipeline (not watch)

   Aim for 1–5 commands per step. A step that is a single trivially-automatable command is fine and desirable.

4. Identify context variables — Note any values that will differ between runs: usernames, branch names, ticket IDs, environment names, file paths. These become context variables, collected once in main() and passed to step functions.

5. Write the do-nothing bash script — Generate the script following the template in references/do_nothing_template.sh. Rules:

   • Shebang: #!/usr/bin/env bash
   • Safety flags: set -euo pipefail immediately after the shebang
   • One function per step, named step_<snake_case_name>()
   • Each function:
     • Prints a heading: echo "==> Step N: <Human readable name>"
     • Prints each sub-command the operator must run, indented with spaces
     • Calls wait_for_enter at the end
   • A wait_for_enter() utility function using read -rp
   • A collect_context() function that prompts for all context variables
   • A main() function that calls collect_context then each step in order, finishing with echo "✓ Done."
   • main "$@" as the last line of the file

6. Annotate automation potential — Add an inline # TODO: automate comment on functions whose body is a single deterministic command. This signals which steps are lowest-effort to convert from manual to automated.

7. Write the script to ./tmp/<name>_do_nothing.sh and make it executable:

   chmod +x ./tmp/<name>_do_nothing.sh
   

8. Validate the script — Run:

   bash -n ./tmp/<name>_do_nothing.sh
   

   Fix any syntax errors reported before presenting the result.

9. Present a summary — Show the operator:

   • The path to the generated script
   • The list of steps and their automation potential
   • A note on which context variables are required at runtime

Notes

• Format auto-detection: extract_commands.py inspects the first line for a JSON header (cast), checks whether the majority of lines match N command (history), and falls back to plain-text otherwise. Use --format= to override when auto-detection is incorrect.
• If the cast file contains only "o" (output) events and no "i" (input) events, extract_commands.py falls back to parsing command prompts from the output stream. Results may be less accurate; review carefully.
• Text file format: Lines beginning with # are treated as comments and skipped. Blank lines are ignored.
• History format: Accepts the output of history (bash/zsh), which prefixes each line with a sequence number: N command.
• Do-nothing scripts are not meant to be run in CI or automation pipelines — they are operator guides. Do not add flags or logic that suppress the interactive prompts.
• When a step involves waiting for an external system (a build, a deploy, a human approval), represent it as a wait_for_enter pause with clear instructions — do not attempt to poll or sleep.
• Step functions should remain pure: no side effects, no file writes, no network calls. The only action they take is printing and waiting.
• Prefer printf over echo for portable output when the string may contain escape sequences; use echo for simple prose lines.