Remove YAML Front Matter

Posted on Edited on

There are many ways to remove YAML Front Matter, here is how I use sed to do so:

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sed -i '1 { /^---/ { :a N; /\n---/! ba; d} }' INPUT_FILE

Explanation:

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1 {              # in the first line
  /^---/ {       # if it starts with ---
    :a           # jump label for looping
    N            # fetch the next line, append to pattern space
    /\n---/! ba; # if the result does not contain \n--- (that is, if the last
                 # fetched line does not begin with ---), go back to :a
    d            # then delete the whole thing.
  }
}
                 # otherwise drop off the end here and do the default (print
                 # the line)

Furthermore, if you wanna keep some useful metadata in front matter like post title in blogging system, you can do so:

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title=$(grep '^title\:\(.*\)$' $1 | sed -e 's/title\:\s//g')
sed -i -e "/---/a # `echo $title`" $1
sed -i '1 { /^---/ { :a N; /\n---/! ba; d} }' $1

Here is a workaround to insert $title in each --- then remove YAML Front Matter.

References: