Linux:后台命令crontab、at

1、crontab使用举例

每天23:00向/tmp/datecon.log文件中写入系统日期

[code]kevin@kevin:/opt/d00148588$crontab -l

no crontab for kevin

kevin@kevin:/opt/d00148588$crontab -e

no crontab for kevin - using an empty one

Select an editor.  To change later, run 'select-editor'.

1. /bin/ed

2. /bin/nano        <---- easiest

3. /usr/bin/emacs23

4. /usr/bin/vim.basic

5. /usr/bin/vim.tiny

Choose 1-5 [2]: 5

crontab: installing new crontab

kevin@kevin:/opt/d00148588$crontab -l

# m h  dom mon dow   command

00 23 * * * /bin/date > /tmp/datecron.log

kevin@kevin:/opt/d00148588$

[/code]

删除crontab文件：

[code]kevin@kevin:/opt/d00148588$crontab -r

kevin@kevin:/opt/d00148588$crontab -l

no crontab for kevin

kevin@kevin:/opt/d00148588$

[/code]

2、at使用举例

23:10向/tmp/dateat.log文件中输入系统日期

[code]kevin@kevin:/opt/d00148588$at 23:10

warning: commands will be executed using /bin/sh

at> date > /tmp/dateat.log

at> <EOT>

job 3 at Thu Sep 13 23:10:00 2012

kevin@kevin:/opt/d00148588$at -l

3    Thu Sep 13 23:10:00 2012 a kevin

kevin@kevin:/opt/d00148588$

[/code]