我如何能快速总结所有号码在一个文件？ [英] How can I quickly sum all numbers in a file?

问题描述

我有一个包含几千个数字的文件中，每个在它自己的行：

I have a file which contains several thousand numbers, each on it's own line:

34
42
11
6
2
99
...

我期待写一个脚本，将打印文件中的所有数字的总和。我有一个解决方案，但它不是很有效。 （这需要几分钟时间。）我正在寻找一个更有效的解决方案。有什么建议？

I'm looking to write a script which will print the sum of all numbers in the file. I've got a solution, but it's not very efficient. (It takes several minutes to run.) I'm looking for a more efficient solution. Any suggestions?

推荐答案

有关一个Perl一行程序，它基本上是同样的事情在<一对 AWK 解决方案href=\"http://stackoverflow.com/questions/2702564/script-to-sum-all-numbers-in-a-file-linux/2702577#2702577\">Ayman Hourieh的回答：

For a Perl one-liner, it's basically the same thing as the awk solution in Ayman Hourieh's answer:

 % perl -nle '$sum += $_ } END { print $sum'

如果你好奇的俏皮话做什么Perl中，你可以deparse他们：

If you're curious what Perl one-liners do, you can deparse them:

 %  perl -MO=Deparse -nle '$sum += $_ } END { print $sum'

结果是该计划的更详细的版本，在一个形式，没有人会写自己的：

The result is a more verbose version of the program, in a form that no one would ever write on their own:

BEGIN { $/ = "\n"; $\ = "\n"; }
LINE: while (defined($_ = <ARGV>)) {
    chomp $_;
    $sum += $_;
}
sub END {
    print $sum;
}
-e syntax OK

只是为了笑声，我想这与含（范围为0 - 9,999）百万数量的文件。在我的Mac Pro，它返回几乎瞬间。这太糟糕了，因为我希望用 MMAP 会非常快，但它只是在同一时间：

Just for giggles, I tried this with a file containing 1,000,000 numbers (in the range 0 - 9,999). On my Mac Pro, it returns virtually instantaneously. That's too bad, because I was hoping using mmap would be really fast, but it's just the same time:

use 5.010;
use File::Map qw(map_file);

map_file my $map, $ARGV[0];

$sum += $1 while $map =~ m/(\d+)/g;

say $sum;

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