Simple Bash script to mirror any Twitter account to a Mastodon account you control.

birdsite_mirror.sh

#!/bin/bash

# birdsite_mirror.sh
# Copyright (c) 2023 Ember Heartshine
#Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
#The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
#THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

# SYSTEM REQUIREMENTS:
#  - python
#  - jq
#  - yq (pip install yq)

# Some notes:
#  - Because this script uses Nitter as a scraper, it cannot handle video posts.
#  - This script is tested working with crontab, assuming a standard python/pip install.
#  - Example crontab assuming the script is located in ~: ~/birdsite_mirror.sh >> ~/birdlog.log 2>&1

# User-friendly name (can be anything, but should not share with others of the same script)
NAME=

# Your Mastodon instance
INSTANCE=

# Mastodon access token; get it from Preferences > Development > $YOUR_APPLICATION
# If you haven't made an application, do so now and get the access token.
# The application MUST have the following permissions: write:media write:statuses
AUTH=

# The Twitter account to monitor (CASE SENSITIVE; I recommend copying straight from the URL)
BIRDACCT=

# The Nitter instance to use (default should be fine unless you have any reason to use another instance)
NITTER=nitter.fly.dev

cd "$(cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd)"
PATH=$PATH":/home/$(whoami)/.local/bin"

if test -f $NAME'_pubdate.txt'; then
	RSS=$(curl -s -L http://$NITTER/$BIRDACCT/rss)
	POSTDATE=$(echo "$RSS" |xq -r '.rss.channel.item[0].pubDate')
	if [[ "$POSTDATE" == 'null' ]]; then
		echo "Error connecting to $NITTER for $NAME. Nothing to do."
	elif [[ "$(cat $NAME'_pubdate.txt')" == "$POSTDATE" ]]; then
		echo "No new $NAME post to fetch."
	else
		DESCRIPTION=$(echo "$RSS" |xq -r '.rss.channel.item[0].description')
		TITLE=$(echo "$RSS" |xq -r '.rss.channel.item[0].title')
		CREATOR=$(echo "$RSS" |xq -r '.rss.channel.item[0]."dc:creator"')
		if [[ $(echo "$DESCRIPTION" |grep '<img' |grep -c -v 'card_img') -gt 0 ]]; then
			FIELDNUM=${NITTER//[^\.]}
			FIELDNUM=$(( 2 + ${#FIELDNUM} ))
			if [[ $(echo "$DESCRIPTION" |sed 's/ /\n/g' |grep -c 'src=') -gt 1 ]]; then
				echo "New album post found for $NAME. Fetching and uploading to Mastodon."
				IMGARR=($(echo "$DESCRIPTION" |sed 's/ /\n/g' |grep 'src=' |cut -d '"' -f2 |tr '\n' ' '))
				for IMAGE in "${IMGARR[@]}"
				do
					EXT=$(echo "$IMAGE" |cut -d '.' -f $FIELDNUM)
					curl -s -L "$IMAGE" -o $NAME.$EXT
					IMGID+=($(curl -s -H "Authorization: Bearer "$AUTH -X POST -H 'Content-Type: multipart/form-data' https://$INSTANCE/api/v2/media --form file="@"$NAME.$EXT |jq -r '.id'))
					rm $NAME.$EXT
				done
			else
				echo "Found new image post for $NAME. Fetching and uploading to Mastodon."
				IMAGE=$(echo "$DESCRIPTION" |sed 's/ /\n/g' |grep 'src=' |cut -d '"' -f2 |head -1)
				EXT=$(echo "$IMAGE" |cut -d '.' -f $FIELDNUM)
				curl -s -L "$IMAGE" -o $NAME.$EXT
				IMGID=$(curl -s -H "Authorization: Bearer "$AUTH -X POST -H 'Content-Type: multipart/form-data' https://$INSTANCE/api/v2/media --form file="@"$NAME.$EXT |jq -r '.id')
				rm $NAME.$EXT
			fi
			TEXT=$(echo "$TITLE" |sed 's/^@/.@/g')
			if [[ $(echo "$CREATOR" |sed s/^@//g) != "$BIRDACCT" ]]; then
				TEXT="From $CREATOR $TEXT"
			fi
			if [[ -n $(echo "$DESCRIPTION" |grep -E "$NITTER/.*/status/") ]]; then
				TEXT="$TEXT"' QT @'$(echo "$DESCRIPTION" |grep -E "$NITTER/.*/status/" |cut -d '/' -f4)': '$(echo "$DESCRIPTION" |grep -E "$NITTER/.*/status/" |cut -d '"' -f2)
			fi
			for ID in "${IMGID[@]}"
			do
				IDFIELD+=( -F 'media_ids[]="'$ID'"' )
			done
			curl -s https://$INSTANCE/api/v1/statuses -H "Authorization: Bearer $AUTH" -F "status=$TEXT" "${IDFIELD[@]}" |jq -r '.url' >> $NAME'_entries.log'
		else
			echo "Found new text post for $NAME. Mirroring to Mastodon."
			TEXT=$(echo "$TITLE" |sed 's/^@/.@/g')
			if [[ $(echo "$CREATOR" |sed s/^@//g) != "$BIRDACCT" ]]; then
				TEXT="From $CREATOR $TEXT"
			fi
			if [[ -n $(echo "$DESCRIPTION" |grep -E "$NITTER/.*/status/") ]]; then
				TEXT="$TEXT"' QT @'$(echo "$DESCRIPTION" |grep -E "$NITTER/.*/status/" |cut -d '/' -f4)': '$(echo "$DESCRIPTION" |grep -E "$NITTER/.*/status/" |cut -d '"' -f2)
			fi
			curl -s https://$INSTANCE/api/v1/statuses -H "Authorization: Bearer "$AUTH -F "status=$TEXT" |jq -r '.url' >> $NAME'_entries.log'
		fi
		echo "$POSTDATE" > $NAME'_pubdate.txt'
	fi
else
	echo 0 > $NAME'_pubdate.txt'
	./${0##*/}
fi