考虑到 YEAR，如何在 CRON 中指定时间? [英] How can I specify time in CRON considering YEAR?

问题描述

我的任务是在考虑 YEAR 字段的 CRON 中指定时间.我该怎么做，或者你知道任何可以在我的 linux 服务器上帮助我的东西吗?谢谢

My task is to specify time in CRON considering YEAR field. How can i do it, or do u know any stuff which can help me on my linux server? thx

推荐答案

如之前的帖子所述，您不能指定年份字段，但是，可以模仿它:

As indicated in earlier posts, you cannot indicate a year field, it is, however, possible to mimic it:

# Example of job definition:
# .---------------- minute (0 - 59)
# |  .------------- hour (0 - 23)
# |  |  .---------- day of month (1 - 31)
# |  |  |  .------- month (1 - 12) OR jan,feb,mar,apr ...
# |  |  |  |  .---- day of week (0 - 6) (Sunday=0 or 7)
# |  |  |  |  |
# *  *  *  *  *   command to be executed
  0  0  1  1  *   [[ $(date "+\%Y") == 2020 ]] && command1
  0  0  1  1  *   (( $(date "+\%Y") % 3 == 0  )) && command2
  0  0  1  1  *   (( $(date "+\%Y") % 3 == 1  )) && command3

这里，command1 将在 2020-01-01T00:00:00 上运行，command2 将在每 3 年的一月一日午夜运行一次，它将在 2019、2022、2025 上运行，......command3 与 command2 的作用相同，但有一年的偏移量，即 2020, 2023, 2026, ...

Here, command1 will run on the 2020-01-01T00:00:00, command2 will run every 3 years on the first of January at midnight, it will run so on 2019, 2022, 2025, ... . command3 does the same as command2 but has one year offset, i.e. 2020, 2023, 2026, ...

注意:不要忘记您必须在 crontab 文件中转义 <percent> 字符 (%):

note: don't forget that you have to escape the <percent>-character (%) in your crontab file:

第六个"字段(行的其余部分)指定要运行的命令.该行的整个命令部分，直到换行符或"%" 字符，将由 /bin/sh 或 cronfile 的 SHELL 变量中指定的 shell 执行.命令中的%"字符，除非用反斜杠()转义，否则会被改成换行符，第一个%<之后的所有数据/code> 将作为标准输入发送到命令.

The "sixth" field (the rest of the line) specifies the command to be run. The entire command portion of the line, up to a newline or a "%" character, will be executed by /bin/sh or by the shell specified in the SHELL variable of the cronfile. A "%" character in the command, unless escaped with a backslash (), will be changed into newline characters, and all data after the first % will be sent to the command as standard input.

_{来源:man 5 crontab}

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