Runs the given markdown file as a bash script, with any failing commands resulting in an error

runmd.sh

#!/bin/bash

# Runs the given markdown file as a bash script, with any failing commands
# resulting in an error
#

set -euo pipefail

if [ "$#" -lt 1 ]
then
    echo "usage: $0 <file> [<filter>]" >&2
    exit 1
fi

DOC="$1"
TERM="${2:-}"

# start from scratch
rm -f $DOC.sh

# grab every bash code block, remove line continuation, and only keep lines
# that start with '$' (of course removing that '$' in the process)
#
sed -n '/``` bash *'"$TERM"'/,/```/{/```/d; p}' $DOC \
    | sed ':a; /\\$/{N; s/\\\n//; ta}' \
    | sed -n '/^\$/{s/^\$ \?//; p}' \
    >> $DOC.sh

# run script
bash -euxo pipefail $DOC.sh