保證已經安裝crontab

yum install crontabs

crontab基本指令

crontab -l   # 列出定時任務列表
crontab -e   # 編輯定時任務

新增需要定時執行的指令碼

# test1.sh
#!/bin/bash
source /etc/profile
function test1()
{
	echo "hello world!";
}

test1

# test2.sh
#!/bin/bash
source /etc/profile
echo "start...";
echo $PWD
source /home/test_shell/test1.sh >>
 
 /home/test_shell/log &
echo "end...";

crontab -e
SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
HOME=/

*/1 * * * * ./home/test_shell/test2.sh  # 定時指令

啟動

systemctl restart crond.service   # 重啟定時任務， 只有restart和reload兩個命令
service cornd status  # 檢視執行報錯情況 

檢視執行和監控

tail -f /var/log/cron    # 執行日誌檢視看
 

tail -f /var/spool/mail/root  # 執行結果日誌

報錯

tail -f /var/log/cron    # 執行日誌查,發現
# 出錯位置
1288 Oct 11 14:13:01 iz2zeglob57mds4wy3xxfbz CROND[22676]: (root) CMD (123 >> /home/test_shell/test2.sh)
1289 Oct 11 14:13:01 iz2zeglob57mds4wy3xxfbz CROND[22675]: (root) MAIL (mailed 32 bytes of output but got status 0x004b#01     2)
 

解決：

檢視是否是路徑問題

*/1 * * * * ./home/test_shell/test2.sh    # 需要放在sh指令碼的絕對路徑

檢視crontab執行轉態

service cornd status
# 報錯
send-mail: fatal: parameter inet_interfaces: no local interface found for ::1

crontab執行會發送郵件，修改postfix的配置檔案 (116行位置)

# The inet_interfaces parameter specifies the network interface
# addresses that this mail system receives mail on.  By default,
# the software claims all active interfaces on the machine. The
# parameter also controls delivery of mail to [email protected][ip.address].
#
# See also the proxy_interfaces parameter, for network addresses that
# are forwarded to us via a proxy or network address translator.
#
# Note: you need to stop/start Postfix when this parameter changes.
#
#inet_interfaces = all
#inet_interfaces = $myhostname
#inet_interfaces = $myhostname, localhost
inet_interfaces = localhost
# Enable IPv4, and IPv6 if supported
inet_protocols = all

改為：

inet_interfaces = all
inet_protocols = all

重啟：

service postfix start 或者
systemctl start postfix.service

最後

在重啟crontab，檢視 /var/spool/mail/root中的結果

From [email protected]  Thu Oct 11 16:30:01 2018
Return-Path: <[email protected]>
X-Original-To: root
Delivered-To: [email protected]
Received: by iz2zeglob57mds4wy3xxfbz.localdomain (Postfix, from userid 0)
	id 43F7540FD4; Thu, 11 Oct 2018 16:30:01 +0800 (CST)
From: "(Cron Daemon)" <[email protected]>
To: [email protected]
Subject: Cron <[email protected]> ./home/test_shell/test2.sh
Content-Type: text/plain; charset=UTF-8
Auto-Submitted: auto-generated
Precedence: bulk
X-Cron-Env: <XDG_SESSION_ID=1090>
X-Cron-Env: <XDG_RUNTIME_DIR=/run/user/0>
X-Cron-Env: <LANG=en_US.UTF-8>
X-Cron-Env: <SHELL=/bin/bash>
X-Cron-Env: <PATH=/sbin:/bin:/usr/sbin:/usr/bin>
X-Cron-Env: <MAILTO=root>
X-Cron-Env: <HOME=/>
X-Cron-Env: <LOGNAME=root>
X-Cron-Env: <USER=root>
Message-Id: <[email protected]>
Date: Thu, 11 Oct 2018 16:30:01 +0800 (CST)

start...
/
end...

這樣就應該可以了！