bash 回合分钟到 5
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bash round minutes to 5
提问by user3408380
We have this string to retrieve date and time in clean format.
我们有这个字符串以干净的格式检索日期和时间。
TIMESTAMP=$(date "+%Y%m%d%H%M")
Is there some inline code that we can use to round the minute to 5 down. So if it is 12:03 it will make it 12:00 and if it is 12:49 it will be 12:45
是否有一些内联代码可以用来将分钟四舍五入到 5。因此，如果是 12:03 则是 12:00，如果是 12:49 则是 12:45
Thank you!
谢谢！
采纳答案by Josh Jolly
To do this you can subtract the minutes modulo 5 from the total minutes. To print it out:
为此，您可以从总分钟数中减去模数 5 的分钟数。打印出来：
echo "$(date "+%Y%m%d%H%M") - ($(date +%M)%5)" | bc
To save it to a variable:
要将其保存到变量：
my_var=$(echo "$(date "+%Y%m%d%H%M") - ($(date +%M)%5)" | bc)
This relies on your date format string remaining as it is now - a string of numbers.
这取决于您现在保留的日期格式字符串 - 一串数字。
Example output:
示例输出：
$ date "+%Y%m%d%H%M"
201404010701
$ echo "$(date "+%Y%m%d%H%M") - ($(date +%M)%5)" | bc
201404010700
回答by glenn Hymanman
A little string manipulation:
一个小的字符串操作：
case $TIMESTAMP in
*[1234]) TIMESTAMP=${TIMESTAMP%?}0;;
*[6789]) TIMESTAMP=${TIMESTAMP%?}5;;
esac
${TIMESTAMP%?}removes the last character. Ref: http://www.gnu.org/software/bash/manual/bashref.html#Shell-Parameter-Expansion
${TIMESTAMP%?}删除最后一个字符。参考：http: //www.gnu.org/software/bash/manual/bashref.html#Shell-Parameter-Expansion
回答by hroptatyr
Not exactly bash only but using dateutils' droundutility, it boils down to:
不完全是 bash 而是使用dateutils 的 dround实用程序，它归结为：
$ dround now -5m
2014-04-01T10:35:00
or with your format specifiers:
或使用您的格式说明符：
$ dround now -5m -f '%Y%m%d%H%M'
201404011035
Disclaimer: I am the author of that project.
免责声明：我是该项目的作者。
回答by fedorqui 'SO stop harming'
You can use the integer division and multiply back to get the round value.
您可以使用整数除法并乘回以获取舍入值。
$ m=23
$ (( m /= 5, m *= 5 )) && echo $m
20
Integer division just return the integer part of the result, so in the case above is returning 4. Then multiplying by 5 gives 20.
整数除法只返回结果的整数部分，所以在上面的例子中返回 4。然后乘以 5 得到 20。
In your case:
在你的情况下：
$ TIMESTAMP=$(date "+%Y%m%d%H%M")
$ echo $TIMESTAMP
201404011231
$ (( TIMESTAMP /= 5, TIMESTAMP *= 5 ))
$ echo $TIMESTAMP
201404011230
$ TIMESTAMP=$(date "+%Y%m%d%H%M")
$ echo $TIMESTAMP
201404011257
$ (( TIMESTAMP /= 5, TIMESTAMP *= 5 ))
$ echo $TIMESTAMP
201404011255
回答by Jasen
using the remainder operator the we can determine the number of excess minutes, that can then be subtracted from the original:
使用余数运算符，我们可以确定超出的分钟数，然后可以从原始值中减去：
TIMESTAMP=$(date "+%Y%m%d%H%M")
(( TIMESTAMP -= TIMESTAMP%15 ))
echo $TIMESTAMP
this only works because both 100 and 60 are divisible by 5 if 15 minutes was wanted instead of 5 the expression would be more complex:
这只有效，因为如果需要 15 分钟而不是 5，则 100 和 60 都可以被 5 整除，表达式会更复杂：
(( TIMESTAMP -= TIMESTAMP%100%5 ))
回答by xerostomus
The solution of Fedorqui is very smart and versatile:
Fedorqui 的解决方案非常智能且通用：
seconds=$(date +%s)
echo $seconds $(date --date="@$seconds" +%H:%M:%S) # say 1559449650 # 06:27:30
# (( seconds /= 3600, seconds *= 3600 )) # rounds to this hour
# (( seconds += 3600, seconds /= 3600, seconds *= 3600 )) # rounds to next hour
(( seconds += 1800, seconds /= 1800, seconds *= 1800 )) # rounds to next half of a hour
next_hour=$(date --date="@$seconds" +%H:%M:%S)
echo $seconds $next_hour # say 1559449800 06:30:00
