COMMENT ⊗   VALID 00002 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002	Test file to see if it is a reasonable source file
C00004 ENDMK
C⊗;
;Test file to see if it is a reasonable source file
NODIR1:	ILDB C,H		;Read a character
NODIR2:	TLNE G,CTAB(C)		;Is it a special one
	JRST NODIR4		;Yes
NODIR3:	SOJG TT,NODIR1		;Try again
	JRST NODIR5		;Something is wrong

NODIR4:	CAIN C,11		;A TAB here is OK
	JRST NODIR3
	CAIE C,15		;Then it must be a CR
	JRST NODIR5		;But it is not
	SOJLE TT,NODIR5		;Have we come to the end?
	ILDB C,H		;Get next character after a CR
	CAIE C,12		;It must be a LF
	JRST NODIR5		;But it is not
	AOS T			;add 1 to count of CRLF's
	CAIL T,4		;Have we found 4 of them?
	JRST NODIR		;Yes so safe to assume text is in ASCII
	SOJLE TT,NODIR5		;At the end yet?
	ILDB C,H		;But now what follows?
	JUMPN C,NODIR2		;Not a NULL
	CAIL T,3		;Have we counted 3 CRLF's?
	JRST NODIR		;Yes so looks OK
	MOVE C,1(H)		;Look for more NULLs,could be a short file
	JUMPE C,NODIR		;Will assume that it is
NODIR5:	OUTSTR [ASCIZ /
Not a normal source file. /]