bash echo 时间日期格式

Question

我已经测试了我需要的格式，但是我无法获得回显输出，请尝试将引号放在不同的位置。

\n

[root@]# date '+%B %V %T.%3N:'\nJuly 29 21:01:24.766:\n

echo 'date \xe2\x80\x99+%B %V %T.%3N:\xe2\x80\x99 %LINK-3-UPDOWN: Interface Port-channel1, changed state to up'\n

预期产出

\n

July 29 21:01:24.766: %LINK-3-UPDOWN: Interface Port-channel1, changed state to up'\n

Answer 1

你可以做：

tm=$(date '+%B %V %T.%3N:')
echo "${tm} %LINK-3-UPDOWN: Interface Port-channel1, changed state to up"

印刷：

July 29 09:22:23.3N: %LINK-3-UPDOWN: Interface Port-channel1, changed state to up

注意双"与单'。只有双引号中的字符串才会在 shell 中进行插值：

bash-5.1$ s1='hello'
bash-5.1$ s2='there'
bash-5.1$ echo "${s1} ${s2}"
hello there

对比：

bash-5.1$ echo '${s1} ${s2}'
${s1} ${s2}

如果你想把所有事情都写在一行中：

echo "$(date '+%B %V %T.%3N:') %LINK-3-UPDOWN: Interface Port-channel1, changed state to up"

或者修改你的date格式字符串：

date '+%B %V %T.%3N: %%LINK-3-UPDOWN: Interface Port-channel1, changed state to up'