Bash Script to Build a Static Website From a Bunch of Markdown Files

build.sh

#!/usr/bin/env bash

# set -euxo pipefail
set -euo pipefail

die() {
  printf "%s\n" "$*" > "$(tty)"
  exit 1
}

get_title() {
  (( $# == 1 )) || die "Usage: get_title \"some_file.md\""
  local pandoc_tmpl="tools/metadata.pandoc-tpl"
  pandoc --template=$pandoc_tmpl "$1" | jq -r '.title'
}

build_html() {
  (( $# == 2 )) || die "Usage: build_html \"input_file.md\" \"output_file.html\""
  local dir_layout="layout"
  cat "$dir_layout/top.html" > "$2"
  pandoc "$1" >> "$2"
  cat "$dir_layout/bottom.html" >> "$2"
}

create_static_assets() {
  (( $# == 1 )) || die "Usage: create_static_assets \"output_dirname\""
  local dir_assets="assets"
  cp -r "$dir_assets"/css "$1"
  cp -r "$dir_assets"/images "$1"
  cp -r "$dir_assets"/as_is/* "$1"
}

replace_in_file() {
  (( $# == 3 )) || die "Usage: replace_in_file \"::SOME_PTTRN::\" \"CONTENT\" \"file.txt\""
  sed -i '' "s/$1/$2/g" "$3"
}

main() {
  local dir_posts="content/posts"
  local dir_pages="content/pages"
  local dir_output="_output"

  [[ -d $dir_output ]] && rm -rf "$dir_output"
  mkdir "$dir_output"

  create_static_assets "$dir_output"

  for input_file in "$dir_posts"/*.md "$dir_pages"/*.md; do
    just_file=$(basename "$input_file" .md)
    output_file="$dir_output/$just_file.html"

    build_html "$input_file" "$output_file"

    title=$(get_title "$input_file")
    replace_in_file "::TITLE::" "$title" "$output_file"
  done
}

main "$@"