string - change string in variable in bash

Question

When I assign in a bash script

DATE=`date`

and

TODAY=${DATE:4:7}

then TODAY contains "Jul 2 " instead of "Jul{2 spaces} ".

So I want to change the first space in $TODAY into two spaces.
How do I do that?
Or how can I avoid the first wrong assignment to $TODAY?

score 2 · Accepted Answer

2

如果你只是想要Jul 2，为什么不使用date选项？

$ date "+%b %-d"
Jul 2

于 2013-07-02T10:25:40.143 回答

score 1 · Accepted Answer

如果您想要当前月份后跟两个空格：

date +'%b  '

或者，对于长名称：

date +'%B  '

要将命令分配给变量，只需使用 $() 运算符，如下所示：

DATE=$(date +'%b  ')

并像这样打印

echo "$DATE is the current month, with more spaces\!"

score 1 · Accepted Answer

您会发现保留了空格：

$ DATE="$(date)"
$ echo "${DATE}"
$ Tue Jul  2 11:43:21 GMT 2013
$ TODAY=${DATE:4:7}
$ echo "*${TODAY}*"
$ *Jul  2 *

score 1 · Accepted Answer

使用日期参数来格式化你想要的日期

date "+%b %_d"

将用空间填充一天，给你所追求的 2 个空间

4 回答 4