Create a new post based in Gatsby. (make sure to create a new-post-template.md file)

new-post.sh

#!/bin/bash

# Print usage if args are missing
if [ -z $1 ]; then
  echo "Usage: new-post <slug>"
  exit
fi

SLUG=$1
DAY=$(date +%Y-%m-%d)
DATE=$(date +%Y-%m-%dT%H:%M:%S%z)
FILE=content/blog/$DAY-$1.md

# Don't overwrite existing posts
if [ -f $FILE ]; then
  echo "That post already exists."
  exit
fi

# Copy the template into place, replacing
# the TITLE and DATE
cat new-post-template.md | sed -e "s/TITLE/$SLUG/g" | sed -e "s/SLUG/$SLUG/g" | sed -e "s/DATE/$DATE/g" > $FILE