使用舍入毫秒 Bash Shell 脚本从时间戳获取格式化日期
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Get Formatted Date From Timestamp With Rounded Milliseconds Bash Shell Script
提问by StuStirling
I need to get a date in a specific format but can't work out how to do it.
我需要获取特定格式的日期，但不知道如何去做。
Here is how I'm getting the date at the moment.
这是我目前获取日期的方式。
date -r "$timestamp" +'%Y-%m-%dT%H:%M:%S.s'
However the issue is the milliseconds has too many digits for the format I need. I need the milliseconds to be limited to 3 digits.
然而问题是毫秒对于我需要的格式有太多的数字。我需要将毫秒限制为 3 位数字。
Any idea how I can do such a thing?
知道我怎么能做这样的事情吗？
Current Workaround
当前的解决方法
Not accurate but it works. I calculate the milliseconds afterwards and then just take the first three characters of the string. Obviously this doesn't take into account round up.
不准确，但它有效。之后我计算毫秒，然后只取字符串的前三个字符。显然，这并没有考虑到四舍五入。
date_string_one=`date -r "$timestamp" +'%Y-%m-%dT%H:%M:%S.'`
date_string_milli=`date -r "$timestamp" +'%s'`
date_string="$date_string_one"`printf "%.3s" "$date_string_milli"`
回答by Joe
You may simply use %3Nto truncate the nanoseconds to the 3 most significant digits:
您可以简单地使用%3N将纳秒截断为 3 个最重要的数字：
$ date +"%Y-%m-%d %H:%M:%S,%3N"
2014-01-08 16:00:12,746
or
或者
$ date +"%F %T,%3N"
2014-01-08 16:00:12,746
testet with ?GNU bash, Version 4.2.25(1)-release (i686-pc-linux-gnu)?
testet 与 ?GNU bash，版本 4.2.25(1)-release (i686-pc-linux-gnu)？
But be aware, that %N may not implemented depending on your target system or bash version.
Tested on an embedded system ?GNU bash, version 4.2.37(2)-release (arm-buildroot-linux-gnueabi)? there was no %N:
但请注意，根据您的目标系统或 bash 版本，%N 可能无法实现。在嵌入式系统上测试？GNU bash，版本 4.2.37(2)-release (arm-buildroot-linux-gnueabi)？没有%N：
date +"%F %T,%N"
2014-01-08 16:44:47,%N
回答by Iamiuru
Million ways to do this.. one simple way is to remove the trailing numbers...
百万种方法来做到这一点.. 一种简单的方法是删除尾随数字...
date +'%Y-%m-%d %H:%M:%S.%N' | sed 's/[0-9][0-9][0-9][0-9][0-9][0-9]$//g'
or
或者
date +'%Y-%m-%d %H:%M:%S.%N' | sed 's/......$//g'
回答by azatar
I can't help offering a "cheap" solution...
我忍不住提供了一个“便宜”的解决方案......
echo $(date +"%Y-%m-%d-%H:%M:%S.")$((RANDOM%1000))
After all, if accuracy is less important than uniqueness, as it is in my case... here you have it.
毕竟，如果准确性不如唯一性那么重要，就像在我的情况下一样......你有它。
回答by cevaris
Best way would be shelling out a python command.
最好的方法是使用 python 命令。
$ python -c "from datetime import datetime; print datetime.utcnow().strftime('%Y-%m-%d %H:%M:%S.%f')[:-3]"
2017-02-15 15:03:03.496
You can then create an alias in you ~/.profile
然后你可以在你里面创建一个别名 ~/.profile
$ alias datetime='python -c python -c "from datetime import datetime;...'
Or even create a shell function
甚至创建一个shell函数
datetime(){
python -c python -c "from datetime import datetime;...
}
回答by punchoyeah
str="2013-04-05 13:33:53.180"
dateStr1=`date -d "$str" +'%Y-%m-%d %H:%M:%S.%N'`;
echo $dateStr1
dateStr2=`date -d "$dateStr1" +'%s'`
echo $dateStr2
dateStr3="$dateStr2"`echo ${dateStr1:20:3}`
echo $dateStr3
============================
[Output]
2013-04-05 13:33:53.180000000
1365140033
1365140033180
(above consider the datestr in UTC)
（以上考虑UTC中的datestr）
回答by jim mcnamara
One problem: %sis not the date format for milliseconds, it is seconds of the current epoch.
%N gives nanoseconds, I do not know of a specified date format for GNU date that gives milliseconds.
一个问题：%s不是毫秒的日期格式，而是当前纪元的秒数。%N 给出了纳秒，我不知道给出毫秒的 GNU 日期的指定日期格式。
Try date --helpto see all of the format options.
尝试date --help查看所有格式选项。
回答by William
Can't think of a way to do it without a couple of steps, but this will get you there:
没有几个步骤就想不出一种方法，但这会让你做到：
d=$(date +'%Y-%m-%d %H:%M:%S|%N')
ms=$(( ${d#*|}/1000000 ))
d="${d%|*}.$ms"
echo $d
2013-04-16 08:51:48.874
Since all the components are taken from a single call to date they'll be consistent.
由于迄今为止所有组件都是从单个调用中获取的，因此它们将保持一致。
回答by chepner
Use printfto do the actual formatting; use dateto produce the set of arguments
printfneeds to fill the format string.
用于printf进行实际格式化；用于date产生printf需要填充格式字符串的参数集
。
printf '%04d-%02d-%02dT%02d:%02d:%02d.%03d' \
$(date -r "${timestamp%.*}" +"%Y %m %d %H %M %S")\
$(( ${timestamp#*.} / 1000 ))
In the above, I assume your timestamp looks something like "blahblahblah.728239". The result is a set of arguments for printflike 2013 04 16 11 03 17 728to produce 2013-04-16T11:03:17.728.
在上面，我假设你的时间戳看起来像“blahblahblah.728239”。结果是一组参数printflike 2013 04 16 11 03 17 728to generate 2013-04-16T11:03:17.728。
