正则表达式仅获取 Perl 中的大写单词

Question

我是 Perl 新手，我一直在做一些作业。

我有一个文件

abc.txt

。它包含

The Bad boy and Good Boy both Went to School

。

我必须编写一个程序来打开文件并仅打印以大写字母开头的单词。

以下是我的程序

my $a = "abc.txt";
open(my $fh,$a) or die "cannot open: $!\n";
while(<$fh>) {
    // I need to add the regex here
    if ($_ =~ /#REGEX HELP PLEASE/)
        # The regex should be generic. The line can change in the file
}

Answer 1

use warnings;
use strict; 

my @array = qw(The Bad boy and Good Boy both Went to School);

foreach (@array){
    if ($_ =~ /([A-Z][a-z])/){ 
        print "$_\n"
    }
}

或者更简单地说：

foreach (@array){
    print "$_\n" if /([A-Z][a-z])/;
}

Answer 2

perl -lne 'push @a,/\b([A-Z][a-z0-9]+)\b/g;END{print join "\n",@a}' your_file

测试：

> cat temp
hello world.
This is hello world.
Another hello world.
New hello World.
The Bad boy and Good Boy both Went to School
>
> perl -lne 'push @a,/\b([A-Z][a-z0-9]+)\b/g;END{print join "\n",@a}' temp
This
Another
New
World
The
Bad
Good
Boy
Went
School
>

Answer 3

怎么样：

while(<$fh>) {
    my @words = split/\W+/,$_;
    foreach (@words) {
        print if /^[A-Z]\w+/;
    }
}

Answer 4

您需要的正则表达式是

/\b[A-Z]+\S*\b/g

，但您可能还需要稍微更改一下代码。

Answer 5

假设

abc.txt

包含行（字符串）“The Bad boy and Good Boy Both Went to School.”，您可以执行以下操作：

use strict;
use warnings;

my $fileName = 'abc.txt';

open my $fh, '<', $fileName or die $!;

while (<$fh>) {
    print $1, "\n" while /([A-Z]\w+)/g;
}

close $fh;

输出：

The
Bad
Good
Boy
Went
School

希望这有帮助！

Answer 6

我认为这会起作用。

my $a = "abc.txt";
open(my $fh,$a) or die "cannot open: $!\n";
while(<$fh>) {
    my @b = split(' ',$_);
    foreach my $c (@b){
        if ($c =~ /([A-Z]\w+)/) {
            print "$1\n";
        }
    }
}

Answer 7

用途：

open(my $fl, 'abc.txt');
while(<$fl>) {
    my @array = split(' ', $_);
    my @results = grep(/([A,Z]\w+)/, @array);
}

Grep 将返回一个列表，其中包含与表达式匹配的

@array

元素。

Answer 8

您首先必须读取文件的每一行。 然后你必须将每一行分成单词。 确定单词是否以大写字母开头的正则表达式只是

if( /^[A-Z]/ ){ #word starts with upper case letter }

整个程序是这样的

#!/usr/bin/perl -w

while(<>){
  my @words = split /\s+/;  #split line into words
  for(@words){
    if(/^[A-Z]/){           #word is upper case
      print "$_\n";
    }
  }
}

输出看起来像这样

$ perl uppercaseWords.pl abc.txt
The
Bad
Good
Boy
Went
School