Question

以下代码显示错误，请帮助我解决代码中的错误

package My::count
use Exporter qw(import);
our @Export_ok=qw(line_count);

sub line_count {
    my $line=@_;
    return $line;
}

我将上面的代码保存在count.pm

中

use My::count qw(line_count);
open INPUT,"<filename.txt";
$line++;
print line count is $line \n";

我将此文件保存在a.pl

中

Answer 1

让我们详细看一下这段代码。

# There's a typo on the line below. It should be /usr/bin/perl
#!usr/bin/perl

# Never comment out these lines.
# Instead, take the time to fix the problems.
# Oh, and it's "warnings", not "warning".
#use strict;
#use warning;

# Always check the return value from open()
# Please use lexical filehandles.
# Please use three-arguments to open().
# open my $ip_fh, '<', 'test1.txt' or die $!;
open IP,"<test1.txt";
my ($line_count,$word_count)=(0,0);

# You're rather fighting against Perl here.
# If you do things in a Perlish manner then it all becomes easier
while(my $line=<IP>) {
  $line_count++;
  my @words_on_this_line= split(" ",$line);
  $word_count+= scalar(@words_on_this_line);
}

print"This file contains $line_count lines\n";
print"this file contains $word_count words\n";

# It all goes a bit wrong here. You don't have an array called @IP.
# I think you wanted to iterate across the file again.
# Either use seek() to return to the start of the file, or store
# the lines in @IP as you're reading them.
# Also, you need to declare $line.
foreach $line(@IP) {
  if ($line =~ /^>/) {
    print $line;
  }
}

close IP;

我会做这样的事情。

#!/usr/bin/perl

use strict;
use warnings;
use 5.010; # for say()

my $filename = shift || die "Must give file name\n";

open my $fh, '<', $filename or die "Can't open $filename: $!\n";

my ($word_count, @matches);

while (<$fh>) {
  # By default, split() splits $_ on whitespace
  my @words_on_line = split;
  $word_count += @words_on_line;
  push @matches, $_ if /^>/;
}

# No need to count lines, Perl does that for us (in $.)
say "This file contains $. lines";
say "This file contains $word_count words";
print @matches;

任何人都可以帮我修复这个脚本中的错误吗？

1 个答案: