handy command line snippets

cli.txt

# description:
#   inserts a new field after an existing field in a yaml file
# scenario:
#   needed to add "comments: true" to all my github page blog posts (*.md)
# explain:
#   -i = edit file in place
#   -e = regex
#   's = substitute
#   find this "/published\:\ true/"
#   replace with this "/published\:\ true/"
#   plus "\ncomments\:\ true/" (note the new line '\n'
#   do this all files that match ".md"
    
sed -i -e 's/published\:\ true/published\:\ true\ncomments\:\ true/' *.md