startfetchmail.sh

#!/bin/sh
# -*- mode: shell-script; sh-basic-offset: 8; tab-width: 8 -*-
# $ startfetchmail.sh $
#
# Created: Wed 06 Mar 2013 17:17:58 EET too
# Last modified: Fri 08 Sep 2017 17:31:02 +0300 too

# Fetchmail does not offer an option to daemonize it after first authentication
# is successful (and report if it failed). After 2 fragile attempts to capture
# the password in one-shot fetch (using tty play) and if that successful
# run fetchmail in daemon mode I've settled to run this script and just check
# from log whether authentication succeeded...

set -euf  # hint: sh -x thisfile [args] to trace execution

case ${1-} in -I) idle=; shift ;; *) idle=idle
esac

case $# in 5) ;; *) exec >&2
	echo
	echo Usage: $0 [-I] '(143|993|995) (keep|nokeep)' user server mda_cmdline
	echo
	echo This script runs fetchmail with options to use encrypted IMAP
	echo '(or POP3)' connection when fetching email. STARTTLS is required
	echo when using port 143. IMAP IDLE feature used when applicable...
	echo
	echo ... except -I option can be used to inhibit IMAP IDLE usage, in
	echo cases where mail delivery is delayed or does not happen with IDLE.
	echo
	echo fetchmail is run in background '(daemon mode)' and first few
	echo seconds of new fetchmail log is printed to terminal so that user
	echo can determine whether authentication succeeded.
	echo
	echo Examples:
	echo
	echo ' ' $0 993 keep $USER mailhost.example.org \\
        echo "          '/usr/bin/procmail -d %T'"
	echo
	echo '    Deliver mail from imap[s] server to user mbox in spool'
	echo '    directory (usually /var[/spool]/mail/$USER, or $MAIL).'
	echo '    Mails are not removed from imap server.'
	echo
	echo ' ' $0 143 nokeep $USER mailhost.example.org \\
        echo "          './nottoomuch/md5mda.sh --cd mail received wip log'"
	echo
	echo '    Deliver mail from imap server (STARTTLS required) to'
	echo '    separate mails in $HOME/mail/received/??/ directories.'
	echo '    Mails are removed from imap server.'
	echo
	exit 1
esac

proto=IMAP
case $1 in 143) ssl='sslproto TLS1'
	;; 993) ssl=ssl
	;; 995) ssl=ssl idle= proto='POP3 uidl' # uidl there is a bit hacky...
	;; *)	exec >&2
		echo
		echo "$0: '$1' is not '143', '993' nor '995'".
		exit 1
		echo
esac

case $2 in keep) keep='keep';; nokeep) keep= ;; *) exec >&2
	echo
	echo "$0: '$2' is not either 'keep' or 'nokeep'".
	echo
	exit 1
esac
shift 2

imap_user=$1 imap_server=$2 mda_cmdline=$3
shift 3
readonly ssl keep imap_server imap_user mda_cmdline

echo cd "$HOME"
cd "$HOME"

mda_cmd=`exec expr "$mda_cmdline" : ' *\([^ ]*\)'`
test -s $mda_cmd || {
	exec >&2
	case $mda_cmd
	in ./*)	echo "Cannot find command '$HOME/$mda_cmd'"
	;; /*)	echo "Cannot find command '$mda_cmd'"
	;; *)	echo "Cannot find command '$HOME/$mda_cmd'"
	esac
	exit 1
}

if test -f .fetchmail.pid
then
	read pid < .fetchmail.pid
	if kill -0 "$pid" 2>/dev/null
	then
		echo "There is (fetchmail) process running in pid $pid"
		ps -p "$pid"
		echo "If this is not fetchmail, remove the file"
		exit 1
	fi
fi

logfile=.fetchmail.log
if test -f $logfile
then
	echo "Rotating logfile '$logfile'"
	mv "$logfile".2 "$logfile".3 2>/dev/null || :
	mv "$logfile".1 "$logfile".2 2>/dev/null || :
	mv "$logfile"   "$logfile".1
fi
touch $logfile

tail -f $logfile &
logfilepid=$!

trap 'rm -f fmconf; kill $logfilepid' 0

umask 077
echo "
set daemon 120
set logfile '$logfile'

poll '$imap_server' proto $proto
  user '$imap_user' $ssl $keep $idle
  mda '$mda_cmdline'
" | tee fmconf

( set -x; exec fetchmail -f fmconf -v )

#x fetchmail -f /dev/null -k -v -p IMAP --ssl --idle -d 120 --logfile $logfile\
#	-u USER --mda '/usr/bin/procmail -d %T' SERVER

sleep 2
test -s $logfile || sleep 2
ol=0
for i in 1 2 3 4 5 6 7 8 9 0
do
	nl=`exec stat -c %s $logfile 2>/dev/null` || break
	test $nl != $ol || break
	ol=$nl
	sleep 1
done
rm -f fmconf
trap '' 15 # TERM may not be supported in all shells...
exec 2>/dev/null # be quiet from no on...
kill $logfilepid
trap - 0 15
echo
ps x | grep '\<fetch[m]ail\>'
echo
echo "Above the end of current fetchmail log '$HOME/$logfile'"
echo "is shown. Check there that your startup was successful."
echo