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
|
implement Redirect;
include "sys.m";
sys : Sys;
include "bufio.m";
bufio : Bufio;
Iobuf : import bufio;
include "string.m";
str : String;
include "redirect.m";
HASHSIZE : con 1019;
Redir: adt{
pat, repl : string;
};
tab := array[HASHSIZE] of list of Redir;
hashasu(key : string,n : int): int
{
i,h : int;
i=0;
h=0;
while(i<len key){
h = 10*h + key[i];
h%= n;
i++;
}
return h;
}
insert(pat, repl : string)
{
hash := hashasu(pat,HASHSIZE);
tab[hash]= Redir(pat, repl) :: tab[hash];
}
redirect_init(file : string)
{
sys = load Sys Sys->PATH;
line : string;
flist : list of string;
n : int;
bb : ref Iobuf;
for(n=0;n<HASHSIZE;n++)
tab[n]= nil;
stderr := sys->fildes(2);
bufio = load Bufio Bufio->PATH;
if (bufio==nil){
sys->fprint(stderr,"redirect: cannot load %s: %r\n", Bufio->PATH);
raise "fail:bad module";
}
str = load String String->PATH;
if (str==nil){
sys->fprint(stderr,"redirect: cannot load %s: %r\n", String->PATH);
raise "fail:bad module";
}
bb = bufio->open(file,bufio->OREAD);
if (bb==nil)
return;
while((line = bb.gets('\n'))!=nil){
line = line[0:len line -1]; #chop newline
if (str->in('#',line)){
(line,nil) = str->splitl(line, "#");
if (line!=nil){
n = len line;
while(line[n]==' '||line[n]=='\t') n--;
# and preceeding blanks
line = line[0:n];
}
}
if (line!=nil){
(n,flist)=sys->tokenize(line,"\t ");
if (n==2)
insert(hd flist,hd tl flist);
}
}
}
lookup(pat : string): ref Redir
{
srch : list of Redir;
tmp : Redir;
hash : int;
hash = hashasu(pat,HASHSIZE);
for(srch = tab[hash]; srch!=nil; srch = tl srch){
tmp = hd srch;
if(tmp.pat==nil)
return nil;
if(pat==tmp.pat)
return ref tmp;
}
return nil;
}
redirect(path : string): string {
redir : ref Redir;
newpath, oldp : string;
s : int;
if((redir = lookup(path))!=nil)
if(redir.repl==nil)
return nil;
else
return redir.repl;
for(s = len path - 1; s>0; s--){
if(path[s]=='/'){
oldp = path[s+1:];
path = path[0:s];
if((redir = lookup(path))!=nil){
if(redir.repl!=nil)
newpath=sys->sprint("%s/%s",
redir.repl,oldp);
else
newpath = nil;
path = path+"/"+oldp;
return newpath;
}
path = path+"/"+oldp;
}
}
return nil;
}
|
