用perl进行多文件行计数，单词计数

 #!/usr/bin/perl
while(<>){
        $count{$ARGV}++;
}
foreach $file (sort by_count keys %count){
        print "$file has $count{$file}\n";
}
sub by_count {
        $count{$a} <=> $count{$b}
}
注意此处sort使用了一个子例程作参数来定义排序规则

如果我们想以从大到小排序可以使用  $count{$b} <=>  $count{$a}

运行结果:

[root@rs1 root]# ./count.pl statistics tcp_deny.txt nohup.out serverstatistics
tcp_deny.txt has 1
serverstatistics has 11
statistics has 22
nohup.out has 3346

上面的程序好象作用不是很大，我们现在变换一下，来进行单词计数

将while中的内容更改一下

while(<>){
        @words=split /\W+/;
        $count{$ARGV}+=@words;
}
这样就可以得到单词排序，

[root@rs1 root]# ./count.pl statistics tcp_deny.txt nohup.out serverstatistics
tcp_deny.txt has 18 words
serverstatistics has 44 words
statistics has 202 words
nohup.out has 39069 words
下面来统计各个单词在所有文件中的数量

#!/usr/bin/perl
while(<>){
        @words=split /\W+/;
        foreach $word (@words){
                $count{$word}++;
        }
}
foreach $word (sort by_count keys %count){
        print "$word occurs $count{$word} times\n";
}
sub by_count {
        $count{$a} <=> $count{$b}
}

运行结果(太长了)的一部分:

[root@rs1 root]# ./count.pl statistics tcp_deny.txt nohup.out serverstatistics
IS6_26_ occurs 1 times
4518452 occurs 1 times
798 occurs 1 times
ORGCODE22_0_ occurs 1 times
load occurs 1 times
col_0_0_ occurs 1 times
 下面来实现单词在每个文件中的计数

#!/usr/bin/perl
while(<>){
        @words=split /\W+/;
        foreach $word (@words){
                $count{$word}{$ARGV}++;
        }
}
foreach $word (sort keys %count){
        foreach $file (sort keys %{$count{$word}}){
                print "$word occurs $count{$word}{$file} times in $file\n";
        }
}
注意学习二维hash的使用 $count{$word}为一个hash引用

让输出更明了些

#!/usr/bin/perl
while(<>){
        @words=split /\W+/;
        foreach $word (@words){
                $count{$word}{$ARGV}++;
        }
}
foreach $word (sort keys %count){
                print "$word:    ",join(",",map "$_:$count{$word}{$_}",keys %{$count{$word}}),"\n";
}

此处要学习一下map 和join的用法哦

如生成这样的结果: