防止shell脚本重复执行的代码

(编辑:jimmy 日期: 2024/12/24 浏览:2)

例如,要求脚本只能顺序访问某个资源,例如磁盘文件等,就可以参考下面的实现。

复制代码 代码如下:
#!/bin/bash
#
# file locking using bash.
# ver 0.1.6
#
# author : malundao ( malundao@sina.com )
# date   : 2011-08-31  
# ref    : http://unix.derkeiler.com/Newsgroups/comp.unix.shell/2005-09/0472.html
#
# note:
#   shflock_cleanhook() is a user defined function to clean up user-specific sth.
#
# /path/to/lock/. note; directory, not a file.
# should be modified
LOCKPATH="/tmp"
cleanup() {
        shflock_cleanhook
        cd $LOCKPATH
        [ -e lock.pid ] || exit
        read pid >/dev/null 2>&1 <lock.pid
        if [ -n "$pid" ]; then
            if [ "$pid" == "$$" ]; then
                rm -f lock.$pid
                rm -f lock.pid
                exit
            fi 
        fi 
        exit
}
#  trap EXIT ?
trap 'cleanup' HUP INT TERM
getlock() {
        oldpath=`pwd`
        cd $LOCKPATH
        while
                echo $$ > lock.$$
                [ -e lock.pid ]
        do
                rm lock.$$
                read pid >/dev/null 2>&1 <lock.pid
                if [ -n "$pid" ]; then
                        if [ -e /proc/$pid ]; then
                                cd $oldpath
                                return 1 # Lock is taken by others
                        else
                                #unsafe: rm -f lock.$pid
                                echo WARN: please delete stale lock.pid by HAND.
                                return 2
                        fi
                else
                        # sleep some seconds,then back to 'while' loop
                        # 11 is a prime number, $$ as a random. 
                        echo sleep $(( $$ % 11 ))
                        sleep $(( $$ % 11 ))
                fi
        done
        # 'ln -s' is an atom op.
        ln -s lock.$$ lock.pid >/dev/null 2>&1
        if [ $? -eq 0 ]; then
                cd $oldpath
                return 0 # We got the lock
        else
                [ -e lock.pid ] || echo WARN: please delete hanging lock.pid by HAND.
                cd $oldpath
                return 3 # Lock is probably taken by others.
        fi
}
putlock () {
    oldpath=`pwd`
    cd $LOCKPATH && rm -f lock.$$ lock.pid
    cd $oldpath
}
## test
shflock_cleanhook() {
    echo i\'m a hook.
}
while true; do
    while ! getlock; do
        #echo wait a second...
        sleep 1
    done
    echo \[$$\] `date` ,now hold lock for 3 seconds...
    sleep 3
    #echo putlock
    putlock
    sleep 1 # yield
done

防止脚本多次执行(一)
复制代码 代码如下:
while [ `ps x |grep -v grep|grep filename.sh|wc -l` -gt 0 ];
do
        exit
done

把内容放在脚本最上面

filename.sh 替换为你要监控的脚本名字
还有一种方法是 死循环 可以根据不同的环境,不同的脚本内容,使用的方法也同步,方法很简单日后在写出来

一句话新闻

一文看懂荣耀MagicBook Pro 16
荣耀猎人回归!七大亮点看懂不只是轻薄本,更是游戏本的MagicBook Pro 16.
人们对于笔记本电脑有一个固有印象:要么轻薄但性能一般,要么性能强劲但笨重臃肿。然而,今年荣耀新推出的MagicBook Pro 16刷新了人们的认知——发布会上,荣耀宣布猎人游戏本正式回归,称其继承了荣耀 HUNTER 基因,并自信地为其打出“轻薄本,更是游戏本”的口号。
众所周知,寻求轻薄本的用户普遍更看重便携性、外观造型、静谧性和打字办公等用机体验,而寻求游戏本的用户则普遍更看重硬件配置、性能释放等硬核指标。把两个看似难以相干的产品融合到一起,我们不禁对它产生了强烈的好奇:作为代表荣耀猎人游戏本的跨界新物种,它究竟做了哪些平衡以兼顾不同人群的各类需求呢?