baskup.sh

#!/bin/sh
BACKUP_DIR=./backup

OS_Version=$(sw_vers -productVersion)
LAST_VERSION=10.13
NEEDS_MODIFICATION=$(echo $OS_Version '>=' $LAST_VERSION | bc -l)
BACKUP_ATTACHMENTS=0

while getopts ":a" opt; do
  case $opt in
    a)
      echo "Running baskup for text + attachments"
      BACKUP_ATTACHMENTS=1
      ;;
    \?)
      echo "Invalid option: -$OPTARG" >&2
      exit 1
      ;;
  esac
done

function select_rows () {
  sqlite3 ~/Library/Messages/chat.db "$1"
}

for line in $(select_rows "select distinct guid from chat;" ); do

  contact=$line
  arrIN=(${contact//;/ })
  contactNumber=${arrIN[2]}
  #Make a directory specifically for this folder
  mkdir -p $BACKUP_DIR/$contactNumber/Attachments

  #Perform SQL operations
  if [[ $NEEDS_MODIFICATION == 1 ]]; then
    select_rows "
    select is_from_me,text, datetime((date/1000000000) + strftime('%s', '2001-01-01 00:00:00'), 'unixepoch', 'localtime') as date from message where handle_id=(
    select handle_id from chat_handle_join where chat_id=(
    select ROWID from chat where guid='$line')
    )" | sed 's/1\|/Me: /g;s/0\|/Friend: /g' > $BACKUP_DIR/$contactNumber/$line.txt
  else
    select_rows "
    select is_from_me,text, datetime(date + strftime('%s', '2001-01-01 00:00:00'), 'unixepoch', 'localtime') as date from message where handle_id=(
    select handle_id from chat_handle_join where chat_id=(
    select ROWID from chat where guid='$line')
    )" | sed 's/1\|/Me: /g;s/0\|/Friend: /g' > $BACKUP_DIR/$contactNumber/$line.txt
  fi

  if [[ $BACKUP_ATTACHMENTS == 1 ]]; then
    select_rows "
    select filename from attachment where rowid in (
    select attachment_id from message_attachment_join where message_id in (
    select rowid from message where cache_has_attachments=1 and handle_id=(
    select handle_id from chat_handle_join where chat_id=(
    select ROWID from chat where guid='$line')
    )))" | cut -c 2- | awk -v home=$HOME '{print home $0}' | tr '\n' '\0' | xargs -0 -I fname cp fname $BACKUP_DIR/$contactNumber/Attachments
  fi

done