I have this script in my bin directory as ~/bin/mktw so that I can quickly and conveniently create or update Tiddlers via the Node.js server listening on port 8080.

#!/bin/bash

TW5URL="http://127.0.0.1:8080"
PROG=${0##*/}

if [ -z "$1" ] ; then
    2>&1 echo "Syntax: cat /tmp/inputfile | $PROG <Tiddler> [tag1] [tag2] [tag3] ..."
    exit 1
else
    TIDDLER="$1"
    shift
fi

function urlencode() {
    echo -n "$*" | python -c 'import urllib,sys; print urllib.quote(sys.stdin.read())'
}

function to_json() {
    echo -n "$*" | python -c 'import json,sys; print json.dumps(sys.stdin.read())'
}

TAGS=""
while (( "$#" )) ; do
    if [ -n "$TAGS" ] ; then
        TAGS="${TAGS}, "
    fi
    TAGS="${TAGS}$(to_json $1)"
    shift
done

An example of how I use it with (one) of my TiddlyWiki's, is to keep a daily copy of my bash history:

#!/bin/bash

YESTERDAY="$(date --date=yesterday +%Y%m%d)"

HISTFILE=~/.bash_history
HISTSIZE=1000
HISTFILESIZE=30000
HISTCONTROL="ignoreboth"
HISTTIMEFORMAT="%Y%m%d %T "

set -o history

(echo '```bash' ; \
  history \
    | grep -P "^\s*[0-9]+\s+${YESTERDAY}\s+" \
    | perl -pe 's/^\s*[0-9]+\s+[0-9]+\s+//' ; \
      echo '```') | ~/bin/mktw "${YESTERDAY}: Bash History" "Bash History"