Batch login system, for fun

login.bat

REM To set up, create a text file called users.txt
REM in the same directory as this batch file
REM with this content (without the REM)
REM 1,user1,password,staff
REM 2,user2,password,pupil

@ECHO OFF
SETLOCAL EnableDelayedExpansion
GOTO main
 
:extract_user
ECHO Finding %2 in %1
ECHO Output: %3

DEL %3
FOR /f %%G IN (%1) DO (
    SET "var=%%G"
    SET "uid=!var:~0,1!"
    ECHO !uid!
	if "!uid!"=="%2" (
		ECHO %%G>>"%3"
	)
)
GOTO :EOF 

:user_parse
SET data=
FOR /f %%G IN (%1) DO (
	SET "data=!data!%%G"
)
SET user_name=
SET user_pass=
SET stage=1
SET "data=!data:~1%!"
SET "data=!data:~1%!"
:username_loop
SET "char=!data:~0,1!"
SET "data=!data:~1%!"
IF "%char%"=="," (
	GOTO password_loop
) ELSE (
	SET "user_name=!user_name!%char%"
)
GOTO username_loop
:password_loop
SET "char=!data:~0,1!"
SET "data=!data:~1%!"
IF "%char%"=="," (
	GOTO rank_loop
) ELSE (
	SET "user_pass=!user_pass!%char%"
)
GOTO password_loop
:rank_loop
GOTO :EOF

:main
SET /p inp_user="Enter your username: " %=%
SET /p inp_pass="Enter your password: " %=%
FOR /f %%G IN (users.txt) DO (
	DEL tmp.txt
	ECHO %%G>>"tmp.txt"
	CALL :user_parse tmp.txt
	IF "!user_name!" == "%inp_user%" (
		if "!user_pass!" == "%inp_pass%" (
			ECHO Logging in...
			GOTO loggedin
		) else (
			GOTO accd
		)
	)
)
:accd
ECHO Access denied
GOTO end

:loggedin
ECHO You are logged in!
PAUSE

:end
ECHO Program Ended
PAUSE