linux-utils/mailsync

#!/bin/sh

maildir=~/mail
# find "$maildir" -mindepth 1 -maxdepth 1 -type d ! -name cur ! -name tmp ! -name new ! -name .notmuch -printf '%f\0' | xargs -0 -n1 --max-procs=0 mbsync
mailboxes=$(find "$maildir" -mindepth 1 -maxdepth 1 -type d ! -name cur ! -name tmp ! -name new ! -name .notmuch -printf '%f\n')

LOCKFILE="/tmp/.mailsync.$USER.lock"
# https://stackoverflow.com/questions/185451/quick-and-dirty-way-to-ensure-only-one-instance-of-a-shell-script-is-running-at
# /!\ locking method is susceptible to race condition
# Should be fine for cron job
if [ -e "$LOCKFILE" ] && kill -0 "$(cat "$LOCKFILE")"; then
    echo "mailsync is already running"
    exit 1
fi

# make sure the lockfile is removed when we exit and then claim it
trap "rm -f $LOCKFILE; exit" INT TERM EXIT
echo $$ > "$LOCKFILE"

for m in $mailboxes; do
    mbsync "$m" &
    sleep 1
done

wait

fdm fetch
notmuch new

rm -f "$LOCKFILE"