1fn webring_init {
 2    switch ($req_path) {
 3    case /prev/*
 4        target=`{echo $req_path | sed 's!^/prev/!!'}
 5        webring_navigate -1 $target
 6        exit
 7    case /next/*
 8        target=`{echo $req_path | sed 's!^/next/!!'}
 9        webring_navigate 1 $target
10        exit
11    case /random
12        webring_random
13        exit
14    }
15}
16
17fn webring_navigate {
18    step = $1
19    pat = $2
20    
21    list_file = $sitedir/list.txt
22
23    num=`{awk -v pat=$pat '$0 ~ pat {print NR; exit}' $list_file}
24
25    if (~ $#num 0) {
26        echo 'Pattern not found in the webring list.'
27        exit
28    }
29
30    lines=`{wc -l < $list_file}
31
32    thing=`{awk -v n=$num -v total=$lines -v step=$step '
33    BEGIN {
34        n = n + step
35        if (n < 1)
36            n = total
37        else if (n > total)
38            n = 1
39    }
40    NR == n {
41        print
42        exit
43    }' $list_file}
44
45    http_redirect $thing '302 Found'
46}
47
48fn webring_random {
49    list_file = $sitedir/list.txt
50
51    lines=`{wc -l < $list_file}
52
53    thing=`{awk -v total=$lines '
54    BEGIN {
55        srand()
56        target = int(rand() * total) + 1
57    }
58    NR == target {
59        print
60        exit
61    }' $list_file}
62
63    if (~ $#thing 0) {
64        echo 'Failed to pick a random site.'
65        exit
66    }
67
68    http_redirect $thing '302 Found'
69}