Add --version and auto-update README (enforced)

.github/workflows/readme-updated.yaml

@@ -0,0 +1,28 @@
+name: Check README.md helptext
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches: [main]
+
+jobs:
+  check_script_and_diff:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v2
+
+    - name: Install duct
+      run: |
+        pip install .
+
+    - name: Update README.md helptext
+      run: |
+        ./.update-readme-help.sh
+
+    - name: Ensure no diff
+      run: |
+        git diff --exit-code

.pre-commit-config.yaml

@@ -29,3 +29,9 @@ repos:
   rev: v2.2.6
   hooks:
   - id: codespell
+- repo: local
+  hooks:
+    - id: update-readme
+      name: Update README with --help output
+      entry: ./.update-readme-help.sh
+      language: system

.update-readme-help.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+duct --help > .help_content.txt
+sed -i '/<\!--- BEGIN HELP -->/,/<\!--- END HELP -->/{//!d;}' README.md
+sed -i '/<\!--- BEGIN HELP -->/r .help_content.txt' README.md
+rm .help_content.txt

CONTRIBUTING.rst

@@ -21,6 +21,20 @@ The following pull request labels are respected:
     * performance: Improve performance of an existing feature
 
 
+Precommit
+---------
+
+The project uses a number of automated checks to limit tedious work.
+The checks will be run automatically prior to commit if `pre-commit` is installed in your
+environment.
+
+`pip install pre-commit`
+
+Note: the README.md is automatically updated to include the helptext, but because argparse changed its
+output in python 3.10+, CI enforces the 3.10+ helptext.
+Please either use 3.10+ or drop the `optional arguments` vs `options` diff.
+
+
 Testing
 -------
 If you are contributing code, please consider adding a unit test.

README.md

@@ -9,20 +9,24 @@ A process wrapper script that monitors the execution of a command.
 ```shell
 > duct --help
 
-usage: duct [-h] [-p OUTPUT_PREFIX] [--sample-interval SAMPLE_INTERVAL]
+<!--- BEGIN HELP -->
+usage: duct [-h] [--version] [-p OUTPUT_PREFIX]
+            [--sample-interval SAMPLE_INTERVAL]
             [--report-interval REPORT_INTERVAL] [-c {all,none,stdout,stderr}]
             [-o {all,none,stdout,stderr}]
             [-t {all,system-summary,processes-samples}]
-            command [arguments ...]
+            command [command_args ...] ...
 
 Gathers metrics on a command and all its child processes.
 
 positional arguments:
-  command               The command to execute.
-  arguments             Arguments for the command. (default: None)
+  command [command_args ...]
+                        The command to execute, along with its arguments.
+  command_args          Arguments for the command.
 
 options:
   -h, --help            show this help message and exit
+  --version             show program's version number and exit
   -p OUTPUT_PREFIX, --output-prefix OUTPUT_PREFIX
                         File string format to be used as a prefix for the
                         files -- the captured stdout and stderr and the
@@ -50,6 +54,7 @@ options:
   -t {all,system-summary,processes-samples}, --record-types {all,system-summary,processes-samples}
                         Record system-summary, processes-samples, or all
                         (default: all)
+<!--- END HELP -->
 ```
 
 ## Testing:

src/duct.py

@@ -212,9 +212,16 @@ def create_and_parse_args():
         description="Gathers metrics on a command and all its child processes.",
         formatter_class=argparse.ArgumentDefaultsHelpFormatter,
     )
-    parser.add_argument("command", help="The command to execute.")
     parser.add_argument(
-        "inner_args", nargs=argparse.REMAINDER, help="Arguments for the command."
+        "command",
+        metavar="command [command_args ...]",
+        help="The command to execute, along with its arguments.",
+    )
+    parser.add_argument(
+        "--version", action="version", version=f"%(prog)s {__version__}"
+    )
+    parser.add_argument(
+        "command_args", nargs=argparse.REMAINDER, help="Arguments for the command."
     )
     parser.add_argument(
         "-p",