q3 shader debugger, checks for bracket mismatches

'quake 3 arena shader debugger by rene breitinger, cc licensed 2016'

#Lang "qb"
Option Explicit

Const shaderfile = "repak-c.shader"

Dim brackets As Integer
Dim inline As String
Dim filehandle As Integer
Dim Lnum As Long

filehandle = Freefile

Open shaderfile For Input As #filehandle

    Do Until Eof( filehandle )
        lnum = lnum  + 1

        Line Input #filehandle, inline

        'check if all brackets were closed before a new shader starts'
        If Left$( lcase$( inline ), 1 ) = "textures/"  And brackets > 0 Then  Goto abnormalexit

        'check opening brackets'
        If Instr( 1, inline, "{" ) <> 0 And brackets <= 2 Then brackets = brackets + 1

        'check closing brackets'
        If Instr (1, inline, "}" ) <> 0 And brackets > 0  Then brackets = brackets - 1

        'check invalid bracket num'
        If brackets < 0 Or brackets > 2 Then Goto abnormalexit
    Loop

Close #filehandle

Print "all shaders parsed; no bracket mismatches found!"
Sleep
End

abnormalexit:
Close #filehandle
Print "error in line "; lnum ,  inline
Sleep
End