开发者

String matching and extraction

开发者 https://www.devze.com 2023-02-24 15:11 出处:网络
I have a string like \"ab.cde.fg.hi\", and I want to split it into two strings. \"ab.cde.fg\" \".hi\" How to do so?I got some开发者_开发百科 code written that will get me the 2nd string but how do

I have a string like "ab.cde.fg.hi", and I want to split it into two strings.

  1. "ab.cde.fg"
  2. ".hi"

How to do so? I got some开发者_开发百科 code written that will get me the 2nd string but how do I retrieve the remaining?

$mystring = "ab.cde.fg";
$mystring =~ m/.*(\..+)/;
print "$1\n";


my ($first, $second) = $string =~ /(.*)(\..*)/;

You can also use split:

my ($first, $second) = split /(?=\.[^.]+$)/, $string;


Are you sure you aren’t looking for...

($name,$path,$suffix) = File::Basename::fileparse($fullname,@suffixlist);


my @parts = /(.*)\.(.*)/s;

my @parts = split /\.(?!.*\.)/s;

my @parts = split /\.(?=[^.]*\z)/s;

Update: I misread. The "." should be included in the second part, but it's not in the above. The above should be:

my @parts = /(.*)(\..*)/s;

my @parts = split /(?=\.(?!.*\.))/s;

my @parts = split /(?=\.[^.]*\z)/s;


To promote my idea to use rindex to get

   1) "ab.cde.fg" 
   2) ".hi"

from "ab.cde.fg.hi", I wrote this script to make experiments easier:

  use strict;
  use diagnostics;
  use warnings;
  use English;

  my @tests = (
      [ 'ab.cde.fg.hi', 'ab.cde.fg|.hi' ]
    , [ 'abxcdexfg.hi', 'abxcdexfg|.hi' ]
  );
  for my $test (@tests) {
    my $src = $test->[0];
    my $exp = $test->[1];
    printf "-----|%s| ==> |%s|-----\n", $src, $exp;
    for my $op (
        [ 'ikegami 1' , sub { shift =~ /(.*)\.(.*)/s; } ]
      , [ 'ikegami 2' , sub { split( /\.(?!.*\.\z)/s, shift) } ]
      , [ 'rindex'    , sub { my $p = rindex( $_[0], '.' );
                              (   substr($_[0], 0, $p)
                                , substr($_[0], $p)
                              ); }
        ]
    ) {
      my ($head, $tail) = $op->[1]( $src );
      my $res = join '|', ($head, $tail);
      my $ok  = $exp eq $res ? 'ok' : "fail: $exp expected.";
      printf "%12s: %-20s => %-20s : %s\n", $op->[0], $src, $res, $ok;
    }
  }

output:

-----|ab.cde.fg.hi| ==> |ab.cde.fg|.hi|-----
   ikegami 1: ab.cde.fg.hi         => ab.cde.fg|hi         : fail: ab.cde.fg|.hi expected.
   ikegami 2: ab.cde.fg.hi         => ab|cde               : fail: ab.cde.fg|.hi expected.
      rindex: ab.cde.fg.hi         => ab.cde.fg|.hi        : ok
-----|abxcdexfg.hi| ==> |abxcdexfg|.hi|-----
   ikegami 1: abxcdexfg.hi         => abxcdexfg|hi         : fail: abxcdexfg|.hi expected.
   ikegami 2: abxcdexfg.hi         => abxcdexfg|hi         : fail: abxcdexfg|.hi expected.
      rindex: abxcdexfg.hi         => abxcdexfg|.hi        : ok
0

精彩评论

暂无评论...
验证码 换一张
取 消

关注公众号