From 2a3fa5b8c749e631d2d7ed1bb01300f023c4b9ea Mon Sep 17 00:00:00 2001
From: Paul Buetow <git@mx.buetow.org>
Date: Tue, 25 May 2021 22:10:09 +0100
Subject: rename packages to lib

---
 lib/assert.source.sh   |  59 ++++++++++++++++++
 lib/atomfeed.source.sh | 128 ++++++++++++++++++++++++++++++++++++++
 lib/gemfeed.source.sh  |  54 +++++++++++++++++
 lib/generate.source.sh | 161 ++++++++++++++++++++++++++++++++++++++++++++++++
 lib/git.source.sh      |  50 +++++++++++++++
 lib/html.source.sh     | 162 +++++++++++++++++++++++++++++++++++++++++++++++++
 lib/log.source.sh      |  30 +++++++++
 lib/md.source.sh       |  63 +++++++++++++++++++
 8 files changed, 707 insertions(+)
 create mode 100644 lib/assert.source.sh
 create mode 100644 lib/atomfeed.source.sh
 create mode 100644 lib/gemfeed.source.sh
 create mode 100644 lib/generate.source.sh
 create mode 100644 lib/git.source.sh
 create mode 100644 lib/html.source.sh
 create mode 100644 lib/log.source.sh
 create mode 100644 lib/md.source.sh

(limited to 'lib')

diff --git a/lib/assert.source.sh b/lib/assert.source.sh
new file mode 100644
index 0000000..d53a728
--- /dev/null
+++ b/lib/assert.source.sh
@@ -0,0 +1,59 @@
+# Unit test for whether 2 given strings equal.
+assert::equals () {
+    local -r result="$1"; shift
+    local -r expected="$1"; shift
+    local -r callee=${FUNCNAME[1]}
+
+    if [[ "$result" != "$expected" ]]; then
+        cat <<ERROR | log::pipe ERROR
+In $callee expected
+    '$expected'
+But got
+    '$result'
+ERROR
+        exit 2
+    fi
+
+    log VERBOSE "Result in $callee as expected: '$expected'"
+}
+
+# Unit test for whether a given string is not empty.
+assert::not_empty () {
+    local -r name="$1"; shift
+    local -r content="$1"; shift
+    local -r callee=${FUNCNAME[1]}
+
+    if [ -z "$content" ]; then
+        log ERROR "In $callee expected '$name' not to be empty!"
+        exit 2
+    fi
+
+    log VERBOSE "Result in $callee as expected not empty"
+}
+
+# Unit test for whether a given string matches a regex.
+assert::matches () {
+    local -r name="$1"; shift
+    local -r content="$1"; shift
+    local -r regex="$1"; shift
+    local -r callee=${FUNCNAME[1]}
+
+    if ! $GREP -q -E "$regex" <<< "$content"; then
+        log ERROR "In $callee expected '$name' to match '$regex'"
+        exit 2
+    fi
+
+    log VERBOSE "Matching in $callee as expected"
+}
+
+# Checks if all the Bash scripts here are good.
+assert::shellcheck () {
+    set -e
+    shellcheck \
+        --norc \
+        --external-sources \
+        --check-sourced \
+        --exclude=SC2155,SC2010,SC2154,SC1090,SC2012 \
+        ./"$0"
+    set +e
+}
diff --git a/lib/atomfeed.source.sh b/lib/atomfeed.source.sh
new file mode 100644
index 0000000..e1ee406
--- /dev/null
+++ b/lib/atomfeed.source.sh
@@ -0,0 +1,128 @@
+# Retrieve meta data of a given blog post. Generate new meta info if not yet exists.
+atomfeed::meta () {
+    local -r gmi_file_path="$1"; shift
+    local -r meta_file=$($SED 's|gemtext|meta|; s|.gmi$|.meta|;' <<< "$gmi_file_path")
+
+    log VERBOSE "Generating meta info for post $gmi_file_path"
+
+    local is_draft=no
+    if $GREP -E -q '\.draft\.meta$' <<< "$meta_file"; then
+        is_draft=yes
+    fi
+
+    local -r meta_dir=$(dirname "$meta_file")
+    if [[ ! -d "$meta_dir" ]]; then
+        mkdir -p "$meta_dir"
+    fi
+
+    if [ ! -f "$meta_file" ]; then
+        # Extract first heading as post title.
+        local title=$($SED -n '/^# / { s/# //; p; q; }' "$gmi_file_path" | tr '"' "'")
+        # Extract first paragraph from Gemtext
+        local summary=$($SED -n '/^[A-Z]/ { p; q; }' "$gmi_file_path" | tr '"' "'")
+        # Extract the date from the file name.
+        local filename_date=$(basename "$gmi_file_path" | cut -d- -f1,2,3)
+        local date=$($DATE --iso-8601=seconds --date "$filename_date $($DATE +%H:%M:%S)")
+
+        cat <<META | tee "$meta_file"
+local meta_date="$date"
+local meta_author="$AUTHOR"
+local meta_email="$EMAIL"
+local meta_title="$title"
+local meta_summary="$summary. .....to read on please visit my site."
+META
+        if [[ $is_draft == no ]]; then
+            git::add meta "$meta_file"
+        fi
+        return
+    fi
+
+    cat "$meta_file"
+    if [[ $is_draft == yes ]]; then
+        rm "$meta_file"
+    fi
+}
+
+# Retrieve the core content as XHTML of the blog post.
+atomfeed::content () {
+    local -r gmi_file_path="$1"; shift
+    log VERBOSE "Retrieving feed content from $gmi_file_path"
+
+    # sed: Remove all before the first header
+    # sed: Make HTML links absolute, Atom relative URLs feature seems a mess
+    # across different Atom clients.
+    html::fromgmi < <($SED '/Go back to the main site/d' "$gmi_file_path") |
+    $SED "
+        s|href=\"\./|href=\"https://$DOMAIN/gemfeed/|g;
+        s|src=\"\./|src=\"https://$DOMAIN/gemfeed/|g;
+    "
+}
+
+# Generate an atom.xml feed file.
+atomfeed::generate () {
+    local -r gemfeed_dir="$CONTENT_BASE_DIR/gemtext/gemfeed"
+    local -r atom_file="$gemfeed_dir/atom.xml"
+    local -r now=$($DATE --iso-8601=seconds)
+    log INFO "Generating Atom feed to $atom_file"
+
+    assert::not_empty now "$now"
+
+    cat <<ATOMHEADER > "$atom_file.tmp"
+<?xml version="1.0" encoding="utf-8"?>
+<feed xmlns="http://www.w3.org/2005/Atom">
+    <updated>$now</updated>
+    <title>$DOMAIN feed</title>
+    <subtitle>$SUBTITLE</subtitle>
+    <link href="gemini://$DOMAIN/gemfeed/atom.xml" rel="self" />
+    <link href="gemini://$DOMAIN/" />
+    <id>gemini://$DOMAIN/</id>
+ATOMHEADER
+
+    while read -r gmi_file; do
+        # Load cached meta information about the post.
+        source <(atomfeed::meta "$gemfeed_dir/$gmi_file")
+
+        # Get HTML content for the feed
+        local content="$(atomfeed::content "$gemfeed_dir/$gmi_file")"
+
+        assert::not_empty meta_title "$meta_title"
+        assert::not_empty meta_date "$meta_date"
+        assert::not_empty meta_author "$meta_author"
+        assert::not_empty meta_email "$meta_email"
+        assert::not_empty meta_summary "$meta_summary"
+        assert::not_empty content "$content"
+
+        cat <<ATOMENTRY >> "$atom_file.tmp"
+    <entry>
+        <title>$meta_title</title>
+        <link href="gemini://$DOMAIN/gemfeed/$gmi_file" />
+        <id>gemini://$DOMAIN/gemfeed/$gmi_file</id>
+        <updated>$meta_date</updated>
+        <author>
+            <name>$meta_author</name>
+            <email>$meta_email</email>
+        </author>
+        <summary>$meta_summary</summary>
+        <content type="xhtml">
+            <div xmlns="http://www.w3.org/1999/xhtml">
+                $content
+            </div>
+        </content>
+    </entry>
+ATOMENTRY
+    done < <(gemfeed::get_posts | head -n $ATOM_MAX_ENTRIES)
+
+    cat <<ATOMFOOTER >> "$atom_file.tmp"
+</feed>
+ATOMFOOTER
+
+    # Delete the 3rd line of the atom feeds (global feed update timestamp)
+    if ! diff -u <($SED 3d "$atom_file") <($SED 3d "$atom_file.tmp"); then
+        log INFO 'Feed got something new!'
+        mv "$atom_file.tmp" "$atom_file"
+        git::add gemtext "$atom_file"
+    else
+        log INFO 'Nothing really new in the feed'
+        rm "$atom_file.tmp"
+    fi
+}
diff --git a/lib/gemfeed.source.sh b/lib/gemfeed.source.sh
new file mode 100644
index 0000000..c842bb1
--- /dev/null
+++ b/lib/gemfeed.source.sh
@@ -0,0 +1,54 @@
+# Filter out blog posts from other files in the gemfeed dir.
+gemfeed::get_posts () {
+    local -r gemfeed_dir="$CONTENT_BASE_DIR/gemtext/gemfeed"
+    local -r gmi_pattern='^[0-9]{4}-[0-9]{2}-[0-9]{2}-.*\.gmi$'
+    local -r draft_pattern='\.draft\.gmi$'
+
+    ls "$gemfeed_dir" |
+        $GREP -E "$gmi_pattern" |
+        $GREP -E -v "$draft_pattern" |
+        sort -r
+}
+
+# Add the links from gemfeed/index.gmi to the main index site.
+gemfeed::updatemainindex () {
+    local -r index_gmi="$CONTENT_BASE_DIR/gemtext/index.gmi"
+    local -r gemfeed_dir="$CONTENT_BASE_DIR/gemtext/gemfeed"
+
+    log VERBOSE "Updating $index_gmi with posts from $gemfeed_dir"
+
+    # Remove old gemfeeds from main index
+    $SED '/^=> .\/gemfeed\/[0-9].* - .*/d;' "$index_gmi" > "$index_gmi.tmp"
+    # Add current gemfeeds to main index
+    $SED -n '/^=> / { s| ./| ./gemfeed/|; p; }' "$gemfeed_dir/index.gmi" >> "$index_gmi.tmp"
+
+    mv "$index_gmi.tmp" "$index_gmi"
+    git::add gemtext "$index_gmi"
+}
+
+# Generate a index.gmi in the ./gemfeed subdir.
+gemfeed::generate () {
+    local -r gemfeed_dir="$CONTENT_BASE_DIR/gemtext/gemfeed"
+    log INFO "Generating Gemfeed index for $gemfeed_dir"
+
+cat <<GEMFEED > "$gemfeed_dir/index.gmi.tmp"
+# $DOMAIN's Gemfeed
+
+## $SUBTITLE
+
+GEMFEED
+
+    gemfeed::get_posts | while read -r gmi_file; do
+        # Extract first heading as post title.
+        local title=$($SED -n '/^# / { s/# //; p; q; }' "$gemfeed_dir/$gmi_file" | tr '"' "'")
+        # Extract the date from the file name.
+        local filename_date=$(basename "$gemfeed_dir/$gmi_file" | cut -d- -f1,2,3)
+
+        echo "=> ./$gmi_file $filename_date - $title" >> "$gemfeed_dir/index.gmi.tmp"
+    done
+
+    mv "$gemfeed_dir/index.gmi.tmp" "$gemfeed_dir/index.gmi"
+    git::add gemtext "$gemfeed_dir/index.gmi"
+
+    gemfeed::updatemainindex
+}
diff --git a/lib/generate.source.sh b/lib/generate.source.sh
new file mode 100644
index 0000000..6f042eb
--- /dev/null
+++ b/lib/generate.source.sh
@@ -0,0 +1,161 @@
+# Generate a HTML or Markdown link from given Gemtext link.
+generate::make_link () {
+    local -r what="$1"; shift
+    local -r line="${1/=> }"; shift
+    local link
+    local descr
+
+    while read -r token; do
+        if [ -z "$link" ]; then
+            link="$token"
+        elif [ -z "$descr" ]; then
+            descr="$token"
+        else
+            descr="$descr $token"
+        fi
+    done < <(echo "$line" | tr ' ' '\n')
+
+    if $GREP -E -q "$IMAGE_PATTERN" <<< "$link"; then
+        if [[ "$what" == md ]]; then
+            md::make_img "$link" "$descr"
+        else
+            html::make_img "$link" "$(html::encode "$descr")"
+        fi
+        return
+    fi
+
+    if [[ "$what" == md ]]; then
+        md::make_link "$link" "$descr"
+    else
+        html::make_link "$link" "$(html::encode "$descr")"
+    fi
+}
+
+# Add other docs (e.g. images, videos) from Gemtext to output format.
+generate::fromgmi_add_docs () {
+    local -r src="$1"; shift
+    local -r format="$1"; shift
+    local -r dest=${src/gemtext/$format}
+    local -r dest_dir=$(dirname "$dest")
+
+    if [[ ! -d "$dest_dir" ]]; then
+        mkdir -p "$dest_dir"
+    fi
+    cp "$src" "$dest"
+    git::add "$format" "$dest"
+}
+
+# Remove docs from output format which aren't present in Gemtext anymore.
+generate::fromgmi_cleanup_docs () {
+    local -r src="$1"; shift
+    local -r format="$1"; shift
+    local dest=${src/.$format/.gmi}
+    dest=${dest/$format/gemtext}
+
+    if [[ ! -f "$dest" ]]; then
+        git::rm "$format" "$src"
+    fi
+}
+
+# Convert the Gemtext Atom feed to a HTML Atom feed.
+generate::convert_gmi_atom_to_html_atom () {
+    local -r format="$1"; shift
+    if [[ "$format" != html ]]; then
+        return
+    fi
+
+    log INFO 'Converting Gemtext Atom feed to HTML Atom feed'
+
+    $SED 's|.gmi|.html|g; s|gemini://|https://|g' \
+        < $CONTENT_BASE_DIR/gemtext/gemfeed/atom.xml \
+        > $CONTENT_BASE_DIR/html/gemfeed/atom.xml
+
+    git::add "$format" "$CONTENT_BASE_DIR/html/gemfeed/atom.xml"
+}
+
+# Internal helper function for generate::fromgmi
+generate::_fromgmi () {
+    local -r src="$1"; shift
+    local -r format="$1"; shift
+    local dest=${src/gemtext/$format}
+    dest=${dest/.gmi/.$format}
+    local dest_dir=$(dirname "$dest")
+
+    if [[ ! -d "$dest_dir" ]]; then
+        mkdir -p "$dest_dir"
+    fi
+
+    if [[ "$format" == html ]]; then
+        cat "$HTML_HEADER" > "$dest.tmp"
+        html::fromgmi < "$src" >> "$dest.tmp"
+        cat "$HTML_FOOTER" >> "$dest.tmp"
+
+    elif [[ "$format" == md ]]; then
+        md::fromgmi < "$src" >> "$dest.tmp"
+    fi
+
+    local title=$($SED -n '/^# / { s/# //; p; q; }' "$src" | tr '"' "'")
+    if [[ -z "$title" ]]; then
+        title=$SUBTITLE
+    fi
+    $SED -i "s|%%TITLE%%|$title|g" "$dest.tmp"
+    mv "$dest.tmp" "$dest"
+
+    git::add "$format" "$dest"
+}
+
+# Generate a given output format from a Gemtext file.
+generate::fromgmi () {
+    local -i num_gmi_files=0
+    local -i num_doc_files=0
+
+    log INFO "Generating $* from Gemtext"
+
+    while read -r src; do
+        num_gmi_files=$(( num_gmi_files + 1 ))
+        for format in "$@"; do
+            generate::_fromgmi "$src" "$format"
+        done
+    done < <(find "$CONTENT_BASE_DIR/gemtext" -type f -name \*.gmi)
+
+    log INFO "Converted $num_gmi_files Gemtext files"
+
+    # Add non-.gmi files to html dir.
+    log VERBOSE "Adding other docs to $*"
+
+    while read -r src; do
+        num_doc_files=$(( num_doc_files + 1 ))
+        for format in "$@"; do
+            generate::fromgmi_add_docs "$src" "$format"
+        done
+    done < <(find "$CONTENT_BASE_DIR/gemtext" -type f | $GREP -E -v '(\.git.*|\.gmi|atom.xml|\.tmp)$')
+
+    log INFO "Added $num_doc_files other documents to each of $*"
+
+    # Add atom feed for HTML
+    for format in "$@"; do
+        generate::convert_gmi_atom_to_html_atom "$format"
+    done
+
+    # Remove obsolete files from ./html/.
+    # Note: The _config.yml is the config file for GitHub pages (md format).
+    # Anoter note: The CNAME file is required by GitHub pages as well for custom domains.
+    for format in "$@"; do
+        find "$CONTENT_BASE_DIR/$format" -type f |
+        $GREP -E -v '(\.git.*|_config.yml|CNAME)$'|
+        while read -r src; do
+            generate::fromgmi_cleanup_docs "$src" "$format"
+        done
+    done
+
+    if [[ -z "$GIT_COMMIT_MESSAGE" ]]; then
+        GIT_COMMIT_MESSAGE='Publishing new version'
+    fi
+    git::commit gemtext "$GIT_COMMIT_MESSAGE"
+    git::commit meta "$GIT_COMMIT_MESSAGE"
+
+    for format in "$@"; do
+        git::commit "$format" "$GIT_COMMIT_MESSAGE"
+        log INFO "$format can be found in $CONTENT_BASE_DIR/$format now"
+    done
+}
diff --git a/lib/git.source.sh b/lib/git.source.sh
new file mode 100644
index 0000000..c502b00
--- /dev/null
+++ b/lib/git.source.sh
@@ -0,0 +1,50 @@
+# Add a static content file to git
+git::add () {
+    if [[ "$USE_GIT" != yes ]]; then
+        return
+    fi
+
+    local -r content_dir="$CONTENT_BASE_DIR/$1"; shift
+    local file="$1"; shift
+    file=${file/$content_dir/.\/}
+
+    cd "$content_dir" &>/dev/null
+    git add "$file"
+    cd - &>/dev/null
+}
+
+# Remove a static content file from git
+git::rm () {
+    if [[ "$USE_GIT" != yes ]]; then
+        return
+    fi
+
+    local -r content_dir="$CONTENT_BASE_DIR/$1"; shift
+    local file="$1"; shift
+    file=${file/$content_dir/.\/}
+
+    cd "$content_dir" &>/dev/null
+    git rm "$file"
+    cd - &>/dev/null
+}
+
+# Commit all changes
+git::commit () {
+    if [[ "$USE_GIT" != yes ]]; then
+        return
+    fi
+
+    local -r content_dir="$CONTENT_BASE_DIR/$1"; shift
+    local -r message="$1"; shift
+
+    cd "$content_dir" &>/dev/null
+    set +e
+    git commit -a -m "$message"
+    if [[ "$GIT_PUSH" == yes ]]; then
+        log INFO "Invoking git pull/push in $content_dir"
+        git pull
+        git push
+    fi
+    set -e
+    cd - &>/dev/null
+}
diff --git a/lib/html.source.sh b/lib/html.source.sh
new file mode 100644
index 0000000..6049c2f
--- /dev/null
+++ b/lib/html.source.sh
@@ -0,0 +1,162 @@
+# Convert special characters to their HTML codes
+html::encode () {
+    $SED '
+        s|\&|\&amp;|g;
+        s|<|\&lt;|g;
+        s|>|\&gt;|g;
+    ' <<< "$@"
+}
+
+# Make a HTML paragraph.
+html::make_paragraph () {
+    local -r text="$1"; shift
+
+    if [[ -n "$text" ]]; then
+        echo "<p>$(html::encode "$text")</p>"
+    fi
+}
+
+# Make a HTML header.
+html::make_heading () {
+    local -r text=$($SED -E 's/^#+ //' <<< "$1"); shift
+    local -r level="$1"; shift
+    echo "<h${level}>$(html::encode "$text")</h${level}>"
+}
+
+# Make a HTML quotation
+html::make_quote () {
+    local -r quote="${1/> }"
+    echo "<p class=\"quote\"><i>$(html::encode "$quote")</i></p>"
+}
+
+# Make a HTML image
+html::make_img () {
+    local link="$1"; shift
+    local descr="$1"; shift
+
+    if [ -z "$descr" ]; then
+        echo -n "<a href=\"$link\"><img src=\"$link\" /></a>"
+    else
+        echo -n "<i>$descr:</i>"
+        echo -n "<a href=\"$link\"><img alt=\"$descr\" title=\"$descr\" src=\"$link\" /></a>"
+    fi
+
+    echo "<br />"
+}
+
+# Make a HTML hyperlink
+html::make_link () {
+    local link="$1"; shift
+    local descr="$1"; shift
+
+    if ! $GREP -F -q '://' <<< "$link"; then
+        link=${link/.gmi/.html}
+    fi
+
+    if [[ -z "$descr" ]]; then
+        descr="$link"
+    fi
+
+    echo "<a class=\"textlink\" href=\"$link\">$descr</a><br />"
+}
+
+# Convert Gemtext to HTML
+html::fromgmi () {
+    local is_list=no
+    local is_plain=no
+
+    while IFS='' read -r line; do
+        if [[ "$is_list" == yes ]]; then
+            if [[ "$line" == '* '* ]]; then
+                echo "<li>$(html::encode "${line/\* /}")</li>"
+            else
+                is_list=no
+                echo "</ul>"
+            fi
+            continue
+
+        elif [[ "$is_plain" == yes ]]; then
+            if [[ "$line" == '```'* ]]; then
+                echo "</pre>"
+                is_plain=no
+            else
+                html::encode "$line"
+            fi
+            continue
+        fi
+
+        case "$line" in
+            '* '*)
+                is_list=yes
+                echo "<ul>"
+                echo "<li>${line/\* /}</li>"
+                ;;
+            '```'*)
+                is_plain=yes
+                echo "<pre>"
+                ;;
+            '# '*)
+                html::make_heading "$line" 1
+                ;;
+            '## '*)
+                html::make_heading "$line" 2
+                ;;
+            '### '*)
+                html::make_heading "$line" 3
+                ;;
+            '> '*)
+                html::make_quote "$line"
+                ;;
+            '=> '*)
+                generate::make_link html "$line"
+                ;;
+            *)
+                html::make_paragraph "$line"
+                ;;
+        esac
+    done
+}
+
+# Test HTML package.
+html::test () {
+    local line='Hello world! This is a paragraph.'
+    assert::equals "$(html::make_paragraph "$line")" '<p>Hello world! This is a paragraph.</p>'
+
+    line=''
+    assert::equals "$(html::make_paragraph "$line")" ''
+
+    line='Foo &<>& Bar!'
+    assert::equals "$(html::make_paragraph "$line")" '<p>Foo &amp;&lt;&gt;&amp; Bar!</p>'
+
+    line='# Header 1'
+    assert::equals "$(html::make_heading "$line" 1)" '<h1>Header 1</h1>'
+
+    line='## Header 2'
+    assert::equals "$(html::make_heading "$line" 2)" '<h2>Header 2</h2>'
+
+    line='### Header 3'
+    assert::equals "$(html::make_heading "$line" 3)" '<h3>Header 3</h3>'
+
+    line='> This is a quote'
+    assert::equals "$(html::make_quote "$line")" '<p class="quote"><i>This is a quote</i></p>'
+
+    line='=> https://example.org'
+    assert::equals "$(generate::make_link html "$line")" \
+        '<a class="textlink" href="https://example.org">https://example.org</a><br />'
+
+    line='=> index.html'
+    assert::equals "$(generate::make_link html "$line")" \
+        '<a class="textlink" href="index.html">index.html</a><br />'
+
+    line='=> http://example.org Description of the link'
+    assert::equals "$(generate::make_link html "$line")" \
+        '<a class="textlink" href="http://example.org">Description of the link</a><br />'
+
+    line='=> http://example.org/image.png'
+    assert::equals "$(generate::make_link html "$line")" \
+        '<a href="http://example.org/image.png"><img src="http://example.org/image.png" /></a><br />'
+
+    line='=> http://example.org/image.png Image description'
+    assert::equals "$(generate::make_link html "$line")" \
+        '<i>Image description:</i><a href="http://example.org/image.png"><img alt="Image description" title="Image description" src="http://example.org/image.png" /></a><br />'
+}
diff --git a/lib/log.source.sh b/lib/log.source.sh
new file mode 100644
index 0000000..56c6587
--- /dev/null
+++ b/lib/log.source.sh
@@ -0,0 +1,30 @@
+# Log a message.
+log () {
+    local -r level="$1"; shift
+    local message
+
+    for message in "$@"; do
+        echo "$message"
+    done | log::_pipe "$level"
+}
+
+# Log a stream through a pipe.
+log::pipe () {
+    log::_pipe "$1"
+}
+
+# Internal log implementation.
+log::_pipe () {
+    local -r level="$1"; shift
+
+    if [[ "$level" == VERBOSE && -z "$LOG_VERBOSE" ]]; then
+        return
+    fi
+
+    local -r callee=${FUNCNAME[2]}
+    local -r stamp=$($DATE +%Y%m%d-%H%M%S)
+
+    while read -r line; do
+        echo "$level|$stamp|$callee|$line" >&2
+    done
+}
diff --git a/lib/md.source.sh b/lib/md.source.sh
new file mode 100644
index 0000000..e7bfae1
--- /dev/null
+++ b/lib/md.source.sh
@@ -0,0 +1,63 @@
+# Make a Markdown image.
+md::make_img () {
+    local link="$1"; shift
+    local descr="$1"; shift
+
+    if [ -z "$descr" ]; then
+        echo "[![$link]($link)]($link)  "
+    else
+        echo "[![$descr]($link \"$descr\")]($link)  "
+    fi
+}
+
+# Make a Markdown hyperlink.
+md::make_link () {
+    local link="$1"; shift
+    local descr="$1"; shift
+
+    if ! $GREP -F -q '://' <<< "$link"; then
+        link=${link/.gmi/.md}
+    fi
+    if [[ -z "$descr" ]]; then
+        descr="$link"
+    fi
+
+    echo "[$descr]($link)  "
+}
+
+# Convert Gemtext to Markdown.
+md::fromgmi () {
+    while IFS='' read -r line; do
+        case "$line" in
+            '=> '*)
+                generate::make_link md "$line"
+                ;;
+            *)
+                echo "$line"
+                ;;
+        esac
+    done
+}
+
+# Test the Markdown package.
+md::test () {
+    local line='=> https://example.org'
+    assert::equals "$(generate::make_link md "$line")" \
+        '[https://example.org](https://example.org)  '
+
+    line='=> index.md'
+    assert::equals "$(generate::make_link md "$line")" \
+        '[index.md](index.md)  '
+
+    line='=> http://example.org Description of the link'
+    assert::equals "$(generate::make_link md "$line")" \
+        '[Description of the link](http://example.org)  '
+
+    line='=> http://example.org/image.png'
+    assert::equals "$(generate::make_link md "$line")" \
+        '[![http://example.org/image.png](http://example.org/image.png)](http://example.org/image.png)  '
+
+    line='=> http://example.org/image.png Image description'
+    assert::equals "$(generate::make_link md "$line")" \
+        '[![Image description](http://example.org/image.png "Image description")](http://example.org/image.png)  '
+}
-- 
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