追加环境变量到Path

 1 @echo off
 2 setlocal enabledelayedexpansion 
 3 
 4 ::使用方法：
 5 :: "C:\WINDOWS"
 6 :: "C:\jar"
 7 SET x="C:\jar"
 8 Call :InPath %x%
 9 goto :eof
10 
11 
12 :InPath
13 SET LocalPathCopy=%PATH%
14 :: whether exist %x%
15 IF "%LocalPathCopy%" == "" GOTO OVER
16 GOTO WHILE
17 
18 :: iterate path variable and check if the first parameter of InPath exists
19 :WHILE
20 FOR /f "delims=; tokens=1,*" %%I IN ("%LocalPathCopy%") DO (
21   set LocalPathCopy=%%J
22   ::echo "%%~I" == "%1" --------- "%LocalPathCopy%"
23   IF /I "%%~I" == %1 (
24     SET Result=1
25     SET x=%%~I
26     echo %x% exists
27     GOTO OVER
28   )
29   GOTO WHILE
30 )
31 
32 :: remove "
33 SET x=%x:"=%
34 
35 IF "!Result!" == "" (
36     echo "%x%" dont exists so we'll add it to path
37     :: you can use SETX command correctly if it exists 
38     :: because the max length of your environment variable cant be great than 1024
39     :: SETX PATH "%Path%;%x%"
40     SET "Path=%Path%;%x%"
41     echo !PATH!
42     GOTO OVER
43 )
44 
45 pause.
46 
47 :OVER
48 PAUSE & GOTO :EOF