#!/bin/bash
##
# Generate html page with blog article excerpts from ./posts.txt. Post file names should
# be added to ./posts.txt in the exact order that they are supposed to appear on the blog
# page.
# Check if required executables can be found
if ! type readlink dirname html2text mv; then
echo 'One or more required executables are not present. Generation cancelled' >&2
exit 1
fi
# Determine script directory (requires GNU readlink)
here="$(dirname "$(readlink -f "${BASH_SOURCE[0]}")")"
printf 'Changing directory: '
pushd "$here" || exit $?
posts_file="$here/posts.txt"
if ! [[ -f "$posts_file" ]]; then
printf 'Posts file "%s" not found. Generation cancelled.\n' "$posts_file" >&2
exit 1
fi
escape-html() {
sed 's/&/\&/g; s//\>/g; s/"/\"/g; s/'"'"'/\'/g'
}
html-to-text() {
html2text -nobs -style compact "$@"
}
blog_html="$here/blog.html"
{
echo '
Blog
Home
Blog
'
while read -r post_html; do
# Convert the post's html to text to make it easier to use the blog's text
text="$(html-to-text "$post_html" | escape-html)" || exit $?
# The title should be on the 2nd line of text, right after the link to the
# homepage. This is a bit inflexible but it will do for now.
title="$(tail -n +2 <<<"$text" | head -n 1 | tr -d '*')" || exit $?
# Use the first 5 lines after the title as post excerpt.
excerpt="$(tail -n +3 <<<"$text" | head -n 5)" || exit $?
# Escape the post html file name to safely use it in the generated html.
href="$(escape-html <<<"$post_html")" || exit $?
printf '
\n' \
"$href" \
"$title" \
"$excerpt"
done < "$posts_file"
echo '
'
} > "$blog_html.new"
mv -v "$blog_html.new" "$blog_html" || exit $?
echo 'SUCCESS!'