取出八的倍數組(第８，１６，２４。。。組)

kfcdog0419

各位前輩好：

小弟欲修改文字檔，概念如下：



有一組具週期性出現的文字檔，只欲取出第八組，第十六組，第二十四組...等等八的倍數組。
請各位前輩救救小弟，萬分感謝。


實際文字檔如下：

10
149.43
20
13.074
10
148.518
20
20.0
10
147.722
20
26.048
10
144.888
20
38.822
10
140.954
20
51.304
10
135.946
20
63.392
10
129.904
20
75.0
10
122.872
20
86.036
10
114.906
20
96.418
10
106.066
20
106.066
10
96.418
20
114.906
10
86.036
20
122.872
10
75.0
20
129.904
10
63.392
20
135.946
10
51.304
20
140.954
10
38.822
20
144.888
10
26.048
20
147.722
10
13.074
20
149.43
10
0.0
20
150.0
10
-13.074
20
149.43
10
-26.048
20
147.722
10
-38.822
20
144.888
10
-51.304
20
140.954
10
-63.392
20
135.946
10
-75.0
20
129.904
10
-86.036
20
122.872
10
-96.418
20
114.906
10
-106.066
20
106.066
10
-114.906
20
96.418
10
-122.872
20
86.036
10
-129.904
20
75.0
10
-135.946
20
63.392
10
-140.954
20
51.304
10
-144.888
20
38.822
10
-147.722
20
26.048
10
-148.518
20
20.0
10
-149.43
20
13.074
10
-150.0
20
0.0
10
-149.43
20
-13.074
10
-147.722
20
-26.048
10
-144.888
20
-38.822
10
-140.954
20
-51.304
10
-135.946
20
-63.392
10
-129.904
20
-75.0
10
-122.872
20
-86.036
10
-114.906
20
-96.418
10
-106.066
20
-106.066
10
-96.418
20
-114.906
10
-86.036
20
-122.872
10
-75.0
20
-129.904
10
-63.392
20
-135.946
10
-51.304
20
-140.954
10
-38.822
20
-144.888
10
-26.048
20
-147.722
10
-13.074
20
-149.43
10
0.0
20
-150.0
10
13.074
20
-149.43
10
26.048
20
-147.722
10
38.822
20
-144.888
10
51.304
20
-140.954
10
63.392
20
-135.946
10
75.0
20
-129.904
10
86.036
20
-122.872
10
96.418
20
-114.906
10
106.066
20
-106.066
10
114.906
20
-96.418
10
122.872
20
-86.036
10
129.904
20
-75.0
10
135.946
20
-63.392
10
140.954
20
-51.304
10
144.888
20
-38.822
10
147.722
20
-26.048
10
149.43
20
-13.074
10
150.0
20
0.0

ntwarren

while(<DATA>){
    chomp;
    $key = ((${.}-1)>>2) + 1;
    push @{$hash{$key}},$_;
}

$key = 8;
while( $hash{$key}){
    print "\n----",$key,"----\n";
    print (join $/,@{$hash{$key}});
    $key = $key <<1;
}


__DATA__
10
149.43
20
13.074
10
148.518
20
20.0
10
147.722
20
26.048
10
144.888
20
38.822
10
140.954
20
51.304
10
135.946
20
63.392
10
129.904
20
75.0
10
122.872
20
86.036
10
114.906
20
96.418
10
106.066
20
106.066
10
96.418
20
114.906
10
86.036
20
122.872
10
75.0
20
129.904
10
63.392
20
135.946
10
51.304
20
140.954
10
38.822
20
144.888
10
26.048
20
147.722
10
13.074
20
149.43
10
0.0
20
150.0
10
-13.074
20
149.43
10
-26.048
20
147.722
10
-38.822
20
144.888
10
-51.304
20
140.954
10
-63.392
20
135.946
10
-75.0
20
129.904
10
-86.036
20
122.872
10
-96.418
20
114.906
10
-106.066
20
106.066
10
-114.906
20
96.418
10
-122.872
20
86.036
10
-129.904
20
75.0
10
-135.946
20
63.392
10
-140.954
20
51.304
10
-144.888
20
38.822
10
-147.722
20
26.048
10
-148.518
20
20.0
10
-149.43
20
13.074
10
-150.0
20
0.0
10
-149.43
20
-13.074
10
-147.722
20
-26.048
10
-144.888
20
-38.822
10
-140.954
20
-51.304
10
-135.946
20
-63.392
10
-129.904
20
-75.0
10
-122.872
20
-86.036
10
-114.906
20
-96.418
10
-106.066
20
-106.066
10
-96.418
20
-114.906
10
-86.036
20
-122.872
10
-75.0
20
-129.904
10
-63.392
20
-135.946
10
-51.304
20
-140.954
10
-38.822
20
-144.888
10
-26.048
20
-147.722
10
-13.074
20
-149.43
10
0.0
20
-150.0
10
13.074
20
-149.43
10
26.048
20
-147.722
10
38.822
20
-144.888
10
51.304
20
-140.954
10
63.392
20
-135.946
10
75.0
20
-129.904
10
86.036
20
-122.872
10
96.418
20
-114.906
10
106.066
20
-106.066
10
114.906
20
-96.418
10
122.872
20
-86.036
10
129.904
20
-75.0
10
135.946
20
-63.392
10
140.954
20
-51.304
10
144.888
20
-38.822
10
147.722
20
-26.048
10
149.43
20
-13.074
10
150.0
20
0.0

ntwarren

while(<DATA>){
    chomp;
    $key = ((${.}-1)>>2) + 1;
    push @{$hash{$key}},$_;
}

$key = 8;
$i = 1;
while( $hash{$key}){
    print "\n----",$key,"----\n";
    print (join $/,@{$hash{$key}});
    $key = 8 * ++$i;
}

huang6894

四行一组，每四行+1，到8后输出改组，并且清零？