batファイルのpause delayのスクリプトコードを説明する。

echo Fs > ss1.txt
ping 192.0.2.2 -n 1 -w 300000 > nul
echo Fs2 > ss2.txt

@echo off
:: Comments are not displayed if echo on
REM comments echo on are displayed

::============================= variable definition ======================================
:: set Set variables
:: set View environment variables
:: set parameter name = parameter value
:: reference variable %variable name%
set aa=rrrrrr
echo %aa%
echo ***********************

::============================== parameter passed to =====================================
::Example 3: A batch of processing files in the C:root directory are named t.bat and have the contents : 
::then run C:\>t a.txt b.txt a.txt b.txt file must exist
::%1 : means a.txt 
::%2 : means b.txt>
REM type %1
REM type %2 

::==============================if else=====================================
::2, if [not] exist [path\]filename Command to be executed 
:: indicates that if the c:\config.sys file exists, its contents are displayed.
if exist c:\en.txt type c:\en.txt
echo ***********************
if not exist c:\en4.txt echo wu
echo ***********************
if exist %cd%\test.LOG (
 echo %cd%\test.LOG
	echo exist!
)
if not exist %cd%\test.LOG (
 echo %cd%\test.LOG
	echo not exist!
)
echo ***********************

IF EXIST \AUTOEXEC.BAT TYPE \AUTOEXEC.BAT 
IF NOT EXIST \AUTOEXEC.BAT ECHO \AUTOEXEC.BAT does not exist 
echo ***********************

::
::If you run: TEST3 A B C the screen will show: 
::XIAO
::TIAN
::XIN
@echo off 
IF "%1" == "A" ECHO XIAO 
IF "%2" == "B" ECHO TIAN 
IF "%3" == "C" ECHO XIN 
echo ***********************

::IF ERRORLEVEL is used to test the return value of its last DOS command.
::Note that it is only the return value of the previous command, and the return values must be judged in order from largest to smallest. Therefore, the following batch file is wrong.
@ECHO OFF 
XCOPY C:\AUTOEXEC.err D: 
IF ERRORLEVEL 1 ECHO AUTOEXEC.err file copy failed 
IF ERRORLEVEL 0 ECHO AUTOEXEC.err successfully copied the file 
echo ***********************

::==============================not if =====================================
::1. if [not] "parameter" == "string" command to be executed 
set ab="abcd"
if %ab%=="abcd" echo equal

::==============================for =====================================
::for Loop command, which will execute the same command multiple times as long as the conditions are met. 
::For example, if a batch file has a line : 
::then this command line will display the contents of all files with bat and txt extensions in the current directory.
::for %%c in (*.bat *.txt) do type %%c 
for %%c in (*.test) do type %%c 
echo ***********************

::Append to the bbb.txt file
echo ***********************1 >>bbb.txt
echo ***********************2 >>bbb.txt
echo ***********************3 >>bbb.txt

::Pause command
pause