C PARSE COMMAND LINE FOR ARGUMENTS
C
C  This subroutine parses a given line into substrings
C corresponding to arguments contained in the line.
C The line may be supplied by the user on entry to the
C subroutine if the first element of <line> is nonzero.
C Otherwise it attempts to retrieve the MCR command line
C which activated the current task.  This will be successful
C if the task was installed with a task name ...XXX and run
C as XXX cmd.line....  It will also work if the task is not
C installed but run as RUN taskname/CMD="XXX cmd.line..."
C Note that in both cases the first word is the command name
C which is skipped by this routine.
C  If it cannot retrieve a command line, the user is prompted
C with a colon for the command line, which is entered without
C the command name at the beginning.
C  It then breaks up the rest of the command line into a
C series of argument substrings.  Each argument is terminated
C by a space or a comma, and may have leading spaces.  Two
C commas together give a zero length argument.
C  The entire command line is returned in <line>, and <iarg>
C is filled with the starting subscript into <line> for each
C argument.  <narg> is set to the actual number of arguments
C found.  <iarg> must be an integer array with at least as
C many elements as there will be arguments.
C  On return, the first argument is LINE(IARG(1)), and has
c length LENGTH(LINE(IARG(1))), and may be treated by use of
C the variable length character string routines.  Each such
C substring is terminated by a zero byte which replaces the
C terminator (comma or space).
C  It also allows command lines which consist of a single
C argument of the form @filename, where the filename must
C include extension.  The routine will then read the first
C line from the named file and use that as the new command
C line.  This line should include the command name before
C the first argument as if it were given to MCR.  This feature
C is used when passing long command lines to routines through
C CCL commands, where only about 40 bytes are available for
C arguments.
C  <line> should be declared as a byte array with at least
C 82 elements.  If the @filename feature is to be used, it
C should have as much as 128 elements.
C
C
C David Villeneuve
C Division of Physics M23A
C National Research Council
C Ottawa Ont. K1A 0R6
C 613-993-9975
C
	SUBROUTINE PARSCL (LINE, IARG, NARG)
	BYTE LINE(1)
	INTEGER IARG(1)
	LOGICAL PAREN
C
C ATTEMPT TO RETRIEVE MCR COMMAND LINE UNLESS LINE IS GIVEN
C
	NARG = 0			!ASSUME NO ARGS
	IFF (LINE(1) .EQ. 0)
	THEN
	    {				!LINE NOT GIVEN ON ENTRY
	    CALL GETMCR (LINE, LLINE)	!ATTEMPT TO RETRIEVE MCR LINE
C
C COULD NOT GET COMMAND LINE, PROMPT FOR ONE
C
10	    IFF (LLINE .LE. 0)
	    THEN
		{			!NO CMD LINE, PROMPT FOR LINE
		WRITE (5,%%)
		FORMAT (' : ', $)
		READ (5,%%) LLINE, (LINE(K),K=1,LLINE)
		FORMAT (Q, 80A1)
		IF (LLINE .LE. 0) RETURN
		LINE(LLINE+1) = 0
		J1 = 1			!NO TASK NAME IN THE LINE
		}
C
C GOT A COMMAND LINE, DROP FIRST NAME ON LINE
C
	    ELSE
		{			!DROP TASK NAME FROM FRONT
		LINE(LLINE+1) = 0
		FOR J1=1,LLINE
		    IF (LINE(J1) .EQ. ' ') GO TO 50
		RETURN			!NO ARGS ON LINE
50
		}
	    }
C
C A LINE WAS GIVEN AS THE FIRST ARGUMENT, USE IT
C
	ELSE
	    {
	    J1 = 1
	    LLINE = 0
	    FOR J=1,4096
		{			!FIND LENGTH OF GIVEN LINE
		IF (LINE(J) .EQ. 0) GO TO 20
		LLINE = LLINE+1
		}
20
	    }
C
C SCAN THROUGH LINE, ENTERING START ADR OF EACH ARG INTO IARG
C
	REPEAT
	    {
	    FOR J=J1,LLINE		!SKIP LEADING BLANKS
	   	IF (LINE(J) .NE. ' ') GO TO 100
	    GO TO 500			!LAST ARG WAS ONLY BLANKS
100	    NARG = NARG+1
	    IARG(NARG) = J		!ENTER ARGUMENT ADR IN TABLE
	    J1 = J
	    PAREN = .FALSE.		!TRUE WHEN INSIDE [uic]

	    FOR J=J1,LLINE		!LOOK FOR END OF ARG
		{
		IFF (LINE(J) .EQ. '[')
		THEN
		    PAREN = .TRUE.
		ELSEIF (LINE(J) .EQ. ']')
		THEN
		    PAREN = .FALSE.
		ELSEIF (.NOT. PAREN .AND. (LINE(J) .EQ. ',' .OR. LINE(J) .EQ. ' ' ))
		THEN
		    GO TO 200
		}
	    GO TO 500			!LAST ARG
C
C PUT ZERO BYTE AT END OF ARGUMENT SUBSTRING
C
200	    LINE(J) = 0			!OVER TOP OF TERMINATOR
	    J1 = J+1			!CONTINUE WITH NEXT CHARACTER
	    }
C
C FINISHED PARSING LINE, CHECK FOR @FILENAME AS FIRST ARGUMENT.
C WE USE LUN 5 FOR THIS SINCE WE DON'T WANT TO TIE UP ANY OTHERS.
C
500	IFF (NARG .EQ. 1 .AND. LINE(IARG(1)) .EQ. '@')
	THEN
	    {
	    CALL CLOSE (5)
	    CALL ASNLUN (5, 'SY', 0)
	    CALL FDBSET (5, 'READONLY')
	    CALL ASSIGN (5, LINE(IARG(1)+1))
	    READ (5,%%) LLINE, (LINE(K), K=1,LLINE)
	    FORMAT (Q, 128A1)
	    CALL CLOSE (5)
	    CALL ASNLUN (5, 'TI', 0)
	    CALL ASSIGN (5, 'TI:')
	    NARG = 0
	    GO TO 10
	    }

	RETURN
	END
	FUNCTION PARVAL (LINE, IARG, NARG, INDEX, DEFALT)
C
C This is a companion routine to PARSCL, which is assumed to have been
C called first.  This routine will return a real number corresponding
C to one of the arguments which was given on the command line.
C The first three arguments are the same as those given in the
C call to PARSCL.  INDEX is the number of the argument which is
C desired, from 1 up.  DEFALT is the default value which is returned
C if the desired argument was not given on the command line.
C
	INTEGER IARG(1)
	BYTE LINE(1)
C
	PARVAL = DEFALT
	IF (INDEX .GT. NARG) RETURN
C
	L = LENGTH( LINE(IARG(INDEX)) )
	IF (L .LE. 0) RETURN
	PARVAL = FPCONV( LINE(IARG(INDEX)), L, 1, LAST )
C
	RETURN
	END