1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
|
subroutine jtmsg(msg,iflag)
! Attempts to identify false decodes in JT-style messages.
! Returns iflag with sum of bits as follows:
! ------------------------------------------
! 1 Grid/Report invalid
! 2 Second callsign invalid
! 4 First callsign invalid
! 8 Very unlikely free text
! 16 Questionable free text
! 0 Message is probably OK
! ------------------------------------------
character*22 msg,t
character*13 w1,w2,w3,w
character*6 bc1,bc2,bc3
character*1 c
logical c1ok,c2ok,c3ok,isdigit,isletter,isgrid4
! Statement functions
isdigit(c)=(ichar(c).ge.ichar('0')) .and. (ichar(c).le.ichar('9'))
isletter(c)=(ichar(c).ge.ichar('A')) .and. (ichar(c).le.ichar('Z'))
isgrid4(w)=(len_trim(w).eq.4 .and. &
ichar(w(1:1)).ge.ichar('A') .and. ichar(w(1:1)).le.ichar('R') .and. &
ichar(w(2:2)).ge.ichar('A') .and. ichar(w(2:2)).le.ichar('R') .and. &
ichar(w(3:3)).ge.ichar('0') .and. ichar(w(3:3)).le.ichar('9') .and. &
ichar(w(4:4)).ge.ichar('0') .and. ichar(w(4:4)).le.ichar('9'))
t=trim(msg) !Temporary copy of msg
nt=len_trim(t)
! Check for standard messages
! Insert underscore in "CQ AA " to "CQ ZZ ", "CQ nnn " to make them one word.
if(t(1:3).eq.'CQ ' .and. isletter(t(4:4)) .and. &
isletter(t(5:5)) .and. t(6:6).eq.' ') t(3:3)='_'
if(t(1:3).eq.'CQ ' .and. isdigit(t(4:4)) .and. &
isdigit(t(5:5)) .and. isdigit(t(6:6)) .and. t(7:7).eq.' ') t(3:3)='_'
! Parse first three words
w1=' '
w2=' '
w3=' '
i1=index(t,' ')
if(i1.gt.0) w1(1:i1-1)=t(1:i1-1)
t=t(i1+1:)
i2=index(t,' ')
if(i2.gt.0) w2(1:i2-1)=t(1:i2-1)
t=t(i2+1:)
i3=index(t,' ')
if(i3.gt.0) w3(1:i3-1)=t(1:i3-1)
if(w1(1:3).eq.'CQ ' .or. w1(1:3).eq.'CQ_' .or. w1(1:3).eq.'DE ' .or. &
w1(1:4).eq.'QRZ ') then
! CQ/DE/QRZ: Should have one good callsign in w2 and maybe a grid/rpt in w3
call chkcall(w2,bc2,c2ok)
iflag=0
if(.not.c2ok) iflag=iflag+2
if(len_trim(w3).ne.0 .and. (.not.isgrid4(w3))) iflag=iflag+1
if(w1(1:3).eq.'DE ' .and. c2ok) iflag=0
if(iflag.eq.0) return
endif
! Check for two calls and maybe a grid, rpt, R+rpr, RRR, or 73
iflag=0
call chkcall(w1,bc1,c1ok)
call chkcall(w2,bc2,c2ok)
if(.not.c1ok) iflag=iflag+4
if(.not.c2ok) iflag=iflag+2
if(len_trim(w3).ne.0 .and. (.not.isgrid4(w3)) .and. &
w3(1:1).ne.'+' .and. w3(1:1).ne.'-' .and. &
w3(1:2).ne.'R+' .and. w3(1:2).ne.'R-' .and. &
w3(1:3).ne.'73 ' .and. w3(1:4).ne.'RRR ') iflag=iflag+1
call chkcall(w3,bc3,c3ok)
! Allow(?) non-standard messages of the form CQ AS OC K1JT
if(w1(1:3).eq.'CQ_'.and.isletter(w2(1:1)).and.isletter(w2(2:2)).and. &
w2(3:3).eq.' '.and.c3ok) iflag=0
if(iflag.eq.0 .or. nt.gt.13) return
! Check for plausible free text
nc=0
np=0
do i=1,13
c=msg(i:i)
if(c.ne.' ') nc=nc+1 !Number of non-blank characters
if(c.eq.'+') np=np+1 !Number of punctuation characters
if(c.eq.'-') np=np+1
if(c.eq.'.') np=np+1
if(c.eq.'/') np=np+1
if(c.eq.'?') np=np+1
enddo
nb=13-nc !Number of blanks
iflag=16 !Mark as potentially questionable
if(nc.ge.12 .or. (nc.ge.11 .and. np.gt.0)) then
iflag=8 !Unlikely free text, flag it
endif
! Save messages containing some common words
if(msg(1:3).eq.'CQ ') iflag=0
if(index(msg,'DE ').gt.0) iflag=0
if(index(msg,'TU ').gt.0) iflag=0
if(index(msg,' TU').gt.0) iflag=0
if(index(msg,'73 ').gt.0) iflag=0
if(index(msg,' 73').gt.0) iflag=0
if(index(msg,'TNX').gt.0) iflag=0
if(index(msg,'THX').gt.0) iflag=0
if(index(msg,'EQSL').gt.0) iflag=0
if(index(msg,'LOTW').gt.0) iflag=0
if(index(msg,'DECOD').gt.0) iflag=0
if(index(msg,'CHK').gt.0) iflag=0
if(index(msg,'CLK').gt.0) iflag=0
if(index(msg,'CLOCK').gt.0) iflag=0
if(index(msg,'LOG').gt.0) iflag=0
if(index(msg,'QRM').gt.0) iflag=0
if(index(msg,'QSY').gt.0) iflag=0
if(index(msg,'TEST').gt.0) iflag=0
if(index(msg,'CQDX').gt.0) iflag=0
if(index(msg,'CALL').gt.0) iflag=0
if(index(msg,'QRZ').gt.0) iflag=0
if(index(msg,'AUTO').gt.0) iflag=0
if(index(msg,'PHOTO').gt.0) iflag=0
if(index(msg,'HYBRID').gt.0) iflag=0
if(c1ok .and. w1(1:6).eq.bc1) iflag=0
if(c2ok .and. w2(1:6).eq.bc2) iflag=0
if(nb.ge.4) iflag=0
return
end subroutine jtmsg
|
