::(双冒号)在 DOS 批处理文件中是什么意思? [英] What does :: (double colon) mean in DOS batch files?

问题描述

我发现了这个程序 web.archive.org:http://baiyunmanor.com/blog/work/get-current-date-time-in-dos-batch-file/

::::::::::::::::::::::::::::::::::::::::::::::::::::::::
::
:: This uses Windows Scripting Host to set variables
:: to the current date/time/day/day_number
:: for Win9x/ME/NT/W2K/XP etc
:: Thanks go to Todd Vargo for his scripting
::::::::::::::::::::::::::::::::::::::::::::::::::::::::
@echo off
set TmpFile="%temp%.	mp.vbs"
echo> %TmpFile% n=Now
echo>>%TmpFile% With WScript
echo>>%TmpFile% .Echo "set year=" + CStr(Year(n))
echo>>%TmpFile% .Echo "set yr=" + Right(Year(n),2)
...
cscript //nologo "%temp%.	mp.vbs" > "%temp%.	mp.bat"
call "%temp%.	mp.bat"
...
echo date F [ddmmyy] [%day%%month%%yr%]
:: datetime.bat

但我不知道线路是什么

:: datetime.bat

最后是什么意思?

推荐答案

:: 是一个标签(不准确的也称为评论标签)可以，在实践中，就像 REM 一样被视为注释，因为它是不可跳转"的标签.

:: is a label (inaccurately also known as comment label) can be, in practice, considered a comment just as REM is, because it is an "un-goto-able" label.

不过，REM 和 :: 之间存在一些区别.主要有:

There are some differences between REM and ::, though. The main ones are:

• 使用 ECHO ON 会显示 REM 行，但没有用 ::

• With ECHO ON a REM line is shown but not a line commented with ::

一个 :: 可以执行一个行尾插入符(即在以 :: 开头的行尾的一个 ^code> 使下一行也成为注释):

A :: can execute a line end caret (that is, a ^ at the end of a line starting with :: makes the next line also a comment):

 :: This is a comment^
 echo but watch out because this line is a comment too

标签和 :: 具有特殊的逻辑，可能会导致括号块出现问题 - 在 ( ).示例:

Labels and :: have a special logic and can cause problems in parentheses blocks - take care when using them inside ( ). Example:

 for %%D in (hi) do (
     echo Before...
     :: My comment
     :: Some other comment
     echo After...
 )

输出:

 Before ...
 The system cannot find the drive specified.
 After...

这篇关于::(双冒号)在 DOS 批处理文件中是什么意思?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！