[Description] Commands that require file names have lexemes that change the lexical state to LFILE so that things like mysrc/foo.txt are recognized as a file name, and not as a variable mysrc being divided by a structure data member foo.txt. [Lexical State] 
LFILE
L B P T
L E X P O R T
L F I L E
L F I N T
L K E Y W O R D
L L I N E
L N O R M
L S E T E N V
L S I G N A L
L W O R D