C	File POSTMAN.FLX
C
C	This is the real-time task that checks for (1) newly
C	logged-in users and (2) users with new mail and
C	notifies them of mail.
C
C	COMMON SGA FOR MAIL, POSTMAN
C
	COMMON /MAICOM/ ENTRY
	BYTE ENTRY (14,20)
	BYTE FILNAM(20)
	INTEGER USRBUF(160)
	INTEGER LUBUF
	LOGICAL*1 EQUAL
	LOGICAL*1 FOUND
	INTEGER IDS,IRET
	BYTE BELL
	EQUIVALENCE (IDS,IRET)
	DATA NENTRY /20/
 
	DATA BELL /7/
	DATA LUBUF /160/
C
C	CODE
C
	SET-UP
	CHECK-FOR-NEW-LOGINS
	CHECK-FOR-NEW-MAIL
	CHECK-FOR-NEW-LOGOUTS
	CALL EXIT
C
	TO SET-UP
C	Get list of logged-in users.
	CALL GETUSR(USRBUF,LUBUF,IER)
C	DEBUGGING CODE
D	CALL DEBUG (1,'POSTMAN.')
D	DO 9991 IUSR=1,LUBUF,8
D9991	IF (USRBUF(IUSR).NE.0) WRITE (3,9903) (USRBUF(I),I=IUSR,IUSR+7)
D9903	FORMAT (1X,6A2,5X,A2,5X,O8)
C	END OF DEBUGGING CODE
	IF (IER.LT.0) TAKE-ERROR-EXIT
C	Suppress non-existent file message
	CALL ERRSET(29,,.FALSE.,,.FALSE.)
C	Suppress "error during write" message
	CALL ERRSET(38,,.FALSE.,,.FALSE.)
	FIN
C
	TO TAKE-ERROR-EXIT
	WRITE (2,101) IDS
101	FORMAT (' Postman exiting with code ',I8,
	1 '. Inform system manager.')
	CALL EXIT
	FIN
C
	TO CHECK-FOR-NEW-MAIL
D	CALL DEBUG (1,' POSTMN: CHECK NEW MAIL')
	DO (IENTRY=1,NENTRY)
	IF (ENTRY(14,IENTRY).NE.0 .AND. ENTRY(1,IENTRY).NE.0)
	IUNIT = ENTRY(13,IENTRY)
D	CALL DEBUG (3,' HAS MAIL: ',ENTRY(1,IENTRY),IUNIT)
	CALL ASNLUN (2,'TT',IUNIT)
	WRITE (2,21,ERR=201) BELL, BELL
21	FORMAT (' ',A1,'     You have mail.',A1/)
	ENTRY(14,IENTRY) = 0
201	CONTINUE
	FIN
	FIN
	FIN
C
	TO CHECK-FOR-NEW-LOGINS
D	CALL DEBUG (1,' POSTMN: CHECK NEW LOGINS',' ')
C	SYSTEM BUG (?): UTN MAY HAVE BLANK NODES
	DO (IUSR = 1,LUBUF,8)
	IF (USRBUF(IUSR+6).EQ.'TT')
	SEARCH-FOR-ENTRY
D	IF (FOUND) CALL DEBUG (3,' ALREADY LOGGED ',ENTRY(1,IENTRY),IUNIT)
	UNLESS (FOUND)
C	Find an empty slot in MAICOM
	IENTRY = 0
	WHILE (IENTRY.LT.NENTRY .AND. .NOT.FOUND)
	IENTRY = IENTRY+1
	FOUND = ENTRY(1,IENTRY) .EQ. 0
	FIN
	IF (FOUND)
	CALL MVSTR (ENTRY(1,IENTRY),USRBUF(IUSR))
	ENTRY (13,IENTRY) = USRBUF(IUSR+7)
D	CALL DEBUG (3,' NEW LOGIN: ',ENTRY(1,IENTRY),USRBUF(IUSR+7))
	ENTRY(14,IENTRY) = 0
	CHECK-FOR-MAIL-FILE
	FIN
	FIN
	FIN
	FIN
	FIN
C
	TO CHECK-FOR-MAIL-FILE
	CALL MVSTR (FILNAM,'[10,0]')
	CALL CONCAT (FILNAM,USRBUF(IUSR))
	CALL CONCAT (FILNAM,'.MAI')
D	CALL DEBUG (2,' TRY FILE ',FILNAM)
	OPEN (NAME=FILNAM,UNIT=1,TYPE='OLD',FORM='FORMATTED',ERR=33)
	WHEN (.FALSE.)
33	CONTINUE
D	CALL DEBUG (1,' NO FILE',' ')
	FIN
	ELSE
	ENTRY(14,IENTRY) = 1
D	CALL DEBUG (1,' FILE FOUND',' ')
	CLOSE (UNIT=1)
	FIN
	FIN
C
	TO SEARCH-FOR-ENTRY
	FOUND = .FALSE.
	IENTRY = 0
	WHILE (IENTRY.LT.NENTRY .AND. .NOT.FOUND)
	IENTRY = IENTRY+1
	IUNIT = ENTRY(13,IENTRY)
	FOUND = EQUAL(ENTRY(1,IENTRY),USRBUF(IUSR)) .AND.
	1 IUNIT .EQ. USRBUF(IUSR+7)
	FIN
	FIN
C
	TO CHECK-FOR-NEW-LOGOUTS
D	CALL DEBUG (1,' POSTMN: CHECK FOR NEW LOGOUTS')
	DO (IENTRY = 1,NENTRY)
	IF (ENTRY(1,IENTRY).NE.0)
	FOUND = .FALSE.
	IUSR = -7
	IUNIT = ENTRY(13,IENTRY)
	WHILE (IUSR.LT.LUBUF .AND. .NOT.FOUND)
	IUSR = IUSR + 8
	FOUND = EQUAL(ENTRY(1,IENTRY),USRBUF(IUSR)) .AND.
	1 IUNIT.EQ.USRBUF(IUSR+7)
	FIN
D	IF (FOUND) CALL DEBUG (3,' STILL LOGGED IN:',
D	1 ENTRY(1,IENTRY),IUNIT)
	UNLESS (FOUND)
D	CALL DEBUG (3,' JUST LOGGED OUT:',ENTRY(1,IENTRY),IUNIT)
	DO (I=1,14) ENTRY(I,IENTRY) = 0
	FIN
	FIN
	FIN
	FIN
C
	END
C
	SUBROUTINE DEBUG(N,LABEL,STRING,IUNIT)
D	BYTE LABEL(1),STRING(1)
D	GOTO (1,2,3),N
D1	WRITE (3,9901) (LABEL(I),I=1,LENGTH(LABEL)-1)
D	RETURN
D2	WRITE (3,9901) (LABEL(I),I=1,LENGTH(LABEL)-1),': ',
D	1 (STRING(I),I=1,LENGTH(STRING)-1)
D	RETURN
D3	WRITE (3,9901) (LABEL(I),I=1,LENGTH(LABEL)-1),': ',
D	1 (STRING(I),I=1,LENGTH(STRING)-1)
D	WRITE (3,9902) IUNIT
D	RETURN
D9901	FORMAT (1X,80A1)
D9902	FORMAT ('+',T40,O5)
	END
C
	SUBROUTINE CONCAT(A,B)
	BYTE A(1),B(1)
	CALL MVSTR(A(LENGTH(A)),B)
	END