防止多重启动的守护进程

daemon.sh

#!/usr/bin/env bash

if [ ! $STY ]; then
    screen -S $(basename $0 .sh) -U -d -m $0 $*
    exit 0
fi

if [ ! $LOCK ]; then
    LOCK=$(echo $0 $* | md5sum | cut -f 1 -d " ").lock
fi
LOCK=~/$LOCK

_cleanup () {
    cleanup
    [ $(jobs -p) ] && kill $(jobs -p)
    [ $(jobs -p) ] && sleep 1
    [ $(jobs -p) ] && sleep 5
    [ $(jobs -p) ] && kill -9 $(jobs -p)
    rm -f $LOCK
    exit 0
}

if [ -f $LOCK ]; then
    LOCK_PID=$(cut -f 1 -d " " $LOCK)
    kill -0 $LOCK_PID && echo "$(date "+%d/%b/%Y:%H:%M:%S") still got $LOCK" || rm -f $LOCK
    exit 1
fi

trap '_cleanup' 0 1 2 3 15 22 24

echo "$$ $(date "+%d/%b/%Y:%H:%M:%S") $0 $*" >> $LOCK
init
FAILED=0
while :
do
    [ ! -f $LOCK ] && exit 1
    [ -f $LOCK ] && [ $(cut -f 1 -d " " $LOCK) -ne $$ ] && exit 1

    START=$( date +%s )
    run
    [ $(jobs -p) ] && wait $(jobs -p)
    STOP=$( date +%s )
    [ $( expr $STOP - $START ) -lt 3 ] && FAILED=$( expr $FAILED + 1 ) || FAILED=0

    if [ -x $(dirname $0)/sendmail.py ]; then
        echo "$$@$(hostname) $(date "+%d/%b/%Y:%H:%M:%S") time:$( expr $STOP - $START ) $0 $*" | $(dirname $0)/sendmail.py "$(hostname) $(basename $0) restart!"
    fi

    [ $FAILED -ge 3 ] && sleep 300
done

example.sh

#!/usr/bin/env bash

init () {
    echo "init"
    cd ~
}

run () {
    echo "run"
    sleep 1
}

cleanup () {
    :
}

source $(dirname $0)/daemon.sh

sendmail.py

#!/usr/bin/env python
# -*- encoding: utf-8 -*-
# vim: set et sw=4 ts=4 sts=4 ff=unix fenc=utf8:
# Author: Binux<huangkuan@duokan.com>
#         http://binux.me
# Created on Wed 11 Jan 2012 04:52:06 PM CST

import sys
import smtplib

from sys import argv as args
from email.mime.text import MIMEText

smtp_host = "smtp.exmail.qq.com"
smtp_port = 465
using_ssl = True

username = ""
password = ""

fromaddr = ""
toaddrs = ["", ]

subject = args[1] if len(args) > 1 else "pysendmail"
msg = sys.stdin.read()

#################################################
outer = MIMEText(msg)
outer['Subject'] = subject
outer['From'] = fromaddr
outer['To'] = ", ".join(toaddrs)
outer.preamble = 'You will not see this in a MIME-aware mail reader.\n'

if using_ssl:
    smtp = smtplib.SMTP_SSL(smtp_host, smtp_port)
else:
    smtp = smtplib.SMTP(smtp_host, smtp_port)
if username and password:
    assert smtp.login(username, password)[0] == 235, "login error"
smtp.sendmail(fromaddr, toaddrs, outer.as_string())

task.sh

#!/usr/bin/env bash

if [ ! $STY ]; then
    screen -S $(basename $0 .sh) -U -d -m $0 $*
    exit 0
fi

if [ ! $LOCK ]; then
    LOCK=$(echo $0 $* | md5sum | cut -f 1 -d " ").lock
fi
LOCK=~/$LOCK

_cleanup () {
    cleanup
    [ $(jobs -p) ] && kill $(jobs -p)
    [ $(jobs -p) ] && sleep 1
    [ $(jobs -p) ] && sleep 5
    [ $(jobs -p) ] && sleep 10
    [ $(jobs -p) ] && kill -9 $(jobs -p)
    rm -f $LOCK
    exit 0
}

if [ -f $LOCK ]; then
    LOCK_PID=$(cut -f 1 -d " " $LOCK)
    kill -0 $LOCK_PID && echo "$(date "+%d/%b/%Y:%H:%M:%S") still got $LOCK" || rm -f $LOCK
    exit 1
fi

trap '_cleanup' 0 1 2 3 15 22 24

echo "$$ $(date "+%d/%b/%Y:%H:%M:%S") $0 $*" >> $LOCK
init
run
[ $(jobs -p) ] && wait $(jobs -p)