上面有很多很好的答案。你也可以使用dotlockfile。

这是一些你可以在你的脚本中使用的示例代码:

$LOCKFILENAME=/var/run/test.lock

if ! dotlockfile -l -p -r 2 $LOCKFILENAME
then
    echo "This test process already running!"
    exit 1
fi

我想要去掉锁文件，锁dirs，特殊的锁程序，甚至pidof，因为它不是在所有的Linux安装中都能找到的。还希望有尽可能简单的代码(或至少尽可能少的行)。最简单的if语句，在一行中:

if [[ $(ps axf | awk -v pid=$$ '$1!=pid && $6~/'$(basename $0)'/{print $1}') ]]; then echo "Already running"; exit; fi

又快又脏?

#!/bin/sh

if [ -f sometempfile ]
  echo "Already running... will now terminate."
  exit
else
  touch sometempfile
fi

..do what you want here..

rm sometempfile

羊群走的路才是正确的。想想当脚本突然失效时会发生什么。在羊群的情况下，你只是松散的羊群，但这不是一个问题。另外，请注意，一个邪恶的伎俩是在脚本本身取一群。但这当然会让您完全陷入权限问题。

下面是一个更优雅、更安全、更快速、更脏的方法，结合了上面提供的答案。

使用

包括sh_lock_functions.sh 使用sh_lock_init初始化 使用sh_acquire_lock进行锁定 使用sh_check_lock检查锁 使用sh_remove_lock解锁

脚本文件

sh_lock_functions.sh

#!/bin/bash

function sh_lock_init {
    sh_lock_scriptName=$(basename $0)
    sh_lock_dir="/tmp/${sh_lock_scriptName}.lock" #lock directory
    sh_lock_file="${sh_lock_dir}/lockPid.txt" #lock file
}

function sh_acquire_lock {
    if mkdir $sh_lock_dir 2>/dev/null; then #check for lock
        echo "$sh_lock_scriptName lock acquired successfully.">&2
        touch $sh_lock_file
        echo $$ > $sh_lock_file # set current pid in lockFile
        return 0
    else
        touch $sh_lock_file
        read sh_lock_lastPID < $sh_lock_file
        if [ ! -z "$sh_lock_lastPID" -a -d /proc/$sh_lock_lastPID ]; then # if lastPID is not null and a process with that pid exists
            echo "$sh_lock_scriptName is already running.">&2
            return 1
        else
            echo "$sh_lock_scriptName stopped during execution, reacquiring lock.">&2
            echo $$ > $sh_lock_file # set current pid in lockFile
            return 2
        fi
    fi
    return 0
}

function sh_check_lock {
    [[ ! -f $sh_lock_file ]] && echo "$sh_lock_scriptName lock file removed.">&2 && return 1
    read sh_lock_lastPID < $sh_lock_file
    [[ $sh_lock_lastPID -ne $$ ]] && echo "$sh_lock_scriptName lock file pid has changed.">&2  && return 2
    echo "$sh_lock_scriptName lock still in place.">&2
    return 0
}

function sh_remove_lock {
    rm -r $sh_lock_dir
}

使用的例子

sh_lock_usage_example.sh

#!/bin/bash
. /path/to/sh_lock_functions.sh # load sh lock functions

sh_lock_init || exit $?

sh_acquire_lock
lockStatus=$?
[[ $lockStatus -eq 1 ]] && exit $lockStatus
[[ $lockStatus -eq 2 ]] && echo "lock is set, do some resume from crash procedures";

#monitoring example
cnt=0
while sh_check_lock # loop while lock is in place
do
    echo "$sh_scriptName running (pid $$)"
    sleep 1
    let cnt++
    [[ $cnt -gt 5 ]] && break
done

#remove lock when process finished
sh_remove_lock || exit $?

exit 0

特性

使用文件、目录和进程id的组合来锁定，以确保进程尚未运行 您可以检测脚本是否在删除锁之前停止(例如。进程终止，关闭，错误等) 您可以检查锁文件，并在丢失锁时使用它来触发进程关闭 Verbose，输出错误消息，以便于调试

下面是一种方法，它结合了原子目录锁定和通过PID检查过期锁，如果过期就重新启动。此外，这并不依赖于任何羞怯。

#!/bin/dash

SCRIPTNAME=$(basename $0)
LOCKDIR="/var/lock/${SCRIPTNAME}"
PIDFILE="${LOCKDIR}/pid"

if ! mkdir $LOCKDIR 2>/dev/null
then
    # lock failed, but check for stale one by checking if the PID is really existing
    PID=$(cat $PIDFILE)
    if ! kill -0 $PID 2>/dev/null
    then
       echo "Removing stale lock of nonexistent PID ${PID}" >&2
       rm -rf $LOCKDIR
       echo "Restarting myself (${SCRIPTNAME})" >&2
       exec "$0" "$@"
    fi
    echo "$SCRIPTNAME is already running, bailing out" >&2
    exit 1
else
    # lock successfully acquired, save PID
    echo $$ > $PIDFILE
fi

trap "rm -rf ${LOCKDIR}" QUIT INT TERM EXIT


echo hello

sleep 30s

echo bye