How does a batch process determine that a parameter contains certain strings? _dos/bat

How does a batch process determine that a parameter contains certain strings?

The general situation to determine when the exact match with = =

Copy Code code as follows:

@echo off
If "%1" = = "abc" @echo OK

But how do you write a partial match? For example, when the first three characters in a parameter are "ABC"

Copy Code code as follows:

@echo off
echo%1|findstr "^ABC" >nul
Echo%errorlevel%

The test results are as follows:

C:\>test Xixi
1

C:\>test
1

C:\>test ABCD
0

C:\>test XABCD
1

Thank you very much, but how do I achieve the effect of if else?

Like what

If '%1 ' contains ' abc ' @echo OK
If '%1 ' contains ' def ' @echo NG

Copy Code code as follows:

@echo off
echo%1|findstr "^ABC" >nul
If%errorlevel% equ 0 (
Echo OK
) Else (
Echo Not OK
)