Give sed and grep example in drop-down box #20

	on:
	push:
	pull_request:
	schedule:
	- cron: "0 0 12 * *"

	name: check-links

	jobs:
	check-links:
	runs-on: ubuntu-latest
	env:
	GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
	steps:
	- uses: actions/checkout@v2

	- name: Remove lines with false positives
	run: \|
	sed -i 's/.check_links.yaml.//g' README.md
	sed -i 's/.check_spelling.yaml.//g' README.md

	# If there is a valid external link that fails,
	# add it to mlc_config.json
	- name: External links must be checked, do not allow '0' in the 'aliveStatusCodes' of mlc_config.json
	run: if [[ $(grep --regexp "[^0-9]0[^0-9]" mlc_config.json \| wc --lines) == "1" ]]; then echo "FOUND"; exit 42; fi

	- name: Internal links must checked, do not allow '400' in the 'aliveStatusCodes' of mlc_config.json
	run: if [[ $(grep --regexp "[^0-9]400[^0-9]" mlc_config.json \| wc --lines) == "1" ]]; then echo "FOUND"; exit 42; fi

	- uses: gaurav-nelson/github-action-markdown-link-check@v1
	with:
	config-file: 'mlc_config.json'

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