create random Hugo content files for theme testing

wikiblog.sh

#!/usr/bin/env bash

# create Hugo content files from random Wikipedia articles;
# requires Pandoc to convert HTML to Markdown
#
read -r -d '' USAGE <<'EOF'

Usage: wikiblog.sh [options]
    -a list of possible authors for an article (selects 1)
    -c list of possible categories (select up to N-1)
    -n number of articles to generate (default 10)
    -s series to assign all articles to
    -t list of possible tags (select up to N-1)
EOF

# http://mywiki.wooledge.org/BashFAQ/026
shuffle() {
   local i tmp size max rand
   size=${#shuffled[*]}
   for ((i=size-1; i>0; i--)); do
      max=$(( 32768 / (i+1) * (i+1) ))
      while (( (rand=$RANDOM) >= max )); do :; done
      rand=$(( rand % (i+1) ))
      tmp=${shuffled[i]}
      shuffled[i]=${shuffled[rand]}
      shuffled[rand]=$tmp
   done
}

# https://gist.github.com/cdown/1163649
urldecode() {
  local url_encoded="${1//+/ }"
  printf '%b' "${url_encoded//%/\\x}"
}

authors=(alice bob carol ted)
categories=(blog home food work pets games movies books music art)
tags=(red orange yellow green blue indigo violet white black grey)
number=10
series=

while getopts ":a:c:n:s:t:" opt; do
  case $opt in
  a)
    IFS=, read -ra authors <<< "$OPTARG"
    ;;
  c)
    IFS=, read -ra categories <<< "$OPTARG"
    ;;
  n)
    number="$OPTARG"
    ;;
  s)
    series="$OPTARG"
    ;;
  t)
    IFS=, read -ra tags <<< "$OPTARG"
    ;;
  \?)
    echo "$USAGE"
    exit 1
    ;;
  esac
done

# if $series is set, make all articles part of it.
if [ "$series" ]; then
  series='series= "'$series'"'
fi

WIKI="https://en.wikipedia.org/wiki/Special:Random"
count=1
while [ $count -le $number ]; do
  # random author
  myauthor=${authors[$((RANDOM % ${#authors[@]}))]}

  # random date in the past ~10 years
  if [ $(uname) = "Darwin" ]; then
    DATE=$(date -r $(( $(date +%s) - $RANDOM * 10000 )) \
      "+%Y-%m-%dT%H:%M:%S")
  else
    DATE=$(date -d @$(( $(date +%s) - $RANDOM * 10000 )) \
      "+%Y-%m-%dT%H:%M:%S")
  fi

  # random wikipedia article
  URL=$(curl -s --max-redirs 0 -I $WIKI | tr -d '\015' |
    awk '/^Location/{print $2}')
  TITLE=$( urldecode $(basename $URL) | tr _ ' ' | sed -e 's/,/, /g' -e 's/  / /')

  # random subset of categories
  shuffled=("${categories[@]}")
  shuffle
  mycats=$(echo ${shuffled[@]:0:$((RANDOM % (${#shuffled[@]} - 1) + 1))} |
    sed -e 's/ /", "/g')

  # random subset of tags
  shuffled=("${tags[@]}")
  shuffle
  mytags=$(echo ${shuffled[@]:0:$((RANDOM % (${#shuffled[@]} - 1) + 1))} |
    sed -e 's/ /", "/g')
  OUT=$(printf "wiki-%03d-%05d.md" $count $RANDOM)

  echo "$count $TITLE"
  cat > $OUT <<EOF
+++
title = "$TITLE"
date = "$DATE"
source = "$URL"
categories = [ "$mycats" ]
tags = [ "$mytags" ]
$series
+++

EOF
  # retrieve the article and use Pandoc to convert it to Markdown
  curl -s "$URL?action=render" | pandoc -f html -t markdown_github >> $OUT

  count=$(( count + 1 ))
done