sed-cheatsheet.md

aliases	category	classification	date	date_modified	draft	id	image	links	local_archive_links	pinned	print	series	tags	title	type
sed-cheatsheet	sed	public	2020-06-01 11:03:09 -0700	2020-06-01 11:03:09 -0700	false	20200601180309				false	false		sed bash linux	sed Cheatsheet	tech-note

# Prepend to beginning of line number:
sed '<line>s/^/hello/' <file>

# Multiple `sed` commands:
sed '337s/^/+++<s>+++/; 337s/$/+++<\/s>+++/' <file>

# Regex to identify numbers as \d{*} doesn't work:
sed 's/?ref=v[0-9]*\.[0-9]*\.[0-9]*//g'

# Takes filename minus ending and appends to image frontmatter path.
for file in *.md; do BOOK=$(basename --suffix=.md $file) && sed --in-place=.orig "7s/$/$BOOK.png/" $file; done

# Replace ## Chapter with frontmatter book name:
for file in *.md; do BOOK=$(grep "book: " $file | sed 's/book: //'); echo $BOOK && sed --in-place=.orig "s/## Chapter/## $BOOK/" $file ; done