linux计划任务

crontab -r #删除所有任务
crontab -l #列出当前的定时任务
crontab -e #编辑crontab内容

第一次使用如果出现如下提示，是选择编辑器

liuyx@myubuntu:/$ crontab -e
no crontab for liuyx - using an empty one

Select an editor.  To change later, run 'select-editor'.
  1. /bin/ed
  2. /bin/nano        <---- easiest
  3. /usr/bin/vim.basic
  4. /usr/bin/vim.tiny

选择vim编辑器

1 2	Choose 1-3 [2]: 3 crontab: installing new crontab

重新选择编辑器
select-editor

执行crontab -e

# Edit this file to introduce tasks to be run by cron.
# 
# Each task to run has to be defined through a single line
# indicating with different fields when the task will be run
# and what command to run for the task
# 
# To define the time you can provide concrete values for
# minute (m), hour (h), day of month (dom), month (mon),
# and day of week (dow) or use '*' in these fields (for 'any').# 
# Notice that tasks will be started based on the cron's system
# daemon's notion of time and timezones.
# 
# Output of the crontab jobs (including errors) is sent through
# email to the user the crontab file belongs to (unless redirected).
# 
# For example, you can run a backup of all your user accounts
# at 5 a.m every week with:
# 0 5 * * 1 tar -zcf /var/backups/home.tgz /home/
# 
# For more information see the manual pages of crontab(5) and cron(8)
# 
# m h  dom mon dow   command
* * * * * /home/xxxx.sh

1 2	ubuntu 系统下用 sudo service cron restart redhat 系统下用 sudo service crond restart

redhat查看日志

1	tail -f /var/log/cron

Ubuntu 需要手动开启 Crontab 计划任务日志
参考 https://www.cnblogs.com/dee0912/p/4479196.html