Author: Jonas Bilinkevicius
How can I find files using wildcards? For example:
1 wildcards('c:\*.txt', 'c:\test.txt') = true
2 wildcards('*.c?g', '123.cfg') = true
3 wildcards('c*.doc', 'doc.doc') = false
Answer:
4 type
5 PathStr = string[128]; { in Delphi 2/3: = string }
6 NameStr = string[12]; { in Delphi 2/3: = string }
7 ExtStr = string[3]; { in Delphi 2/3: = string }
8
9 {$V-}
10 { in Delphi 2/ 3 to switch off "strict var-strings" }
11
12 function WildComp(FileWild, FileIs: PathStr): boolean;
13 var
14 NameW, NameI: NameStr;
15 ExtW, ExtI: ExtStr;
16 c: Byte;
17
18 function WComp(var WildS, IstS: NameStr): boolean;
19 var
20 i, j, l, p: Byte;
21 begin
22 i := 1;
23 j := 1;
24 while (i <= length(WildS)) do
25 begin
26 if WildS[i] = '*' then
27 begin
28 if i = length(WildS) then
29 begin
30 WComp := true;
31 exit
32 end
33 else
34 begin
35 { we need to synchronize }
36 l := i + 1;
37 while (l < length(WildS)) and (WildS[l + 1] <> '*') do
38 inc(l);
39 p := pos(copy(WildS, i + 1, l - i), IstS);
40 if p > 0 then
41 begin
42 j := p - 1;
43 end
44 else
45 begin
46 WComp := false;
47 exit;
48 end;
49 end;
50 end
51 else if (WildS[i] <> '?') and ((length(IstS) < i) or (WildS[i] <> IstS[j]))
52 then
53 begin
54 WComp := false;
55 exit
56 end;
57 inc(i);
58 inc(j);
59 end;
60 WComp := (j > length(IstS));
61 end;
62
63 begin
64 c := pos('.', FileWild);
65 if c = 0 then
66 begin { automatically append .* }
67 NameW := FileWild;
68 ExtW := '*';
69 end
70 else
71 begin
72 NameW := copy(FileWild, 1, c - 1);
73 ExtW := copy(FileWild, c + 1, 255);
74 end;
75 c := pos('.', FileIs);
76 if c = 0 then
77 c := length(FileIs) + 1;
78 NameI := copy(FileIs, 1, c - 1);
79 ExtI := copy(FileIs, c + 1, 255);
80 WildComp := WComp(NameW, NameI) and WComp(ExtW, ExtI);
81 end;
82
83 { Example }
84 begin
85 if WildComp('a*.bmp', 'auto.bmp') then
86 ShowMessage('OK 1');
87 if not WildComp('a*x.bmp', 'auto.bmp') then
88 ShowMessage('OK 2');
89 if WildComp('a*o.bmp', 'auto.bmp') then
90 ShowMessage('OK 3');
91 if not WildComp('a*tu.bmp', 'auto.bmp') then
92 ShowMessage('OK 4');
93 end;
94
95 end.
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