使用perl解析abnf语法

Question

感谢您发布在链接Parse::ABNF perl usage处的问题输入。我仍然面临着解决我的问题的困难。请求下面检查我的问题，并提供解决方案的指针。

现在我已经在ABNF格式的文件中创建了sip语法（命名为sip.abnf）。 我有报头的SIP消息在一个文件中像下面（recd_message.txt）：

From: <sip:07455900064@212.136.178.216:5060;user=phone>;tag=1526438727-1338998848384- 
To: "govoice-lab2-aokanlawon"<sip:441127653485@isf.fire.ipgcom.com> 
Contact: <sip:07455900064@10.12.33.29:5070;transport=udp> 
Allow: ACK,BYE,CANCEL,INFO,INVITE,OPTIONS,PRACK,REFER,NOTIFY 
Accept: multipart/mixed,application/media_control+xml,application/sdp 

我创建一个Perl程序使用的ABNF语法与验证它命名为上述头信息作为testSipHeader.pl以下内容：

use strict; use warnings; 
use File::Slurp; 
use Parse::ABNF ; 
use Data::Dumper; 

my $grammar_file = shift; 
my $messages = shift; 
my @header_name; 
my $header_status; 

my $grammar = scalar read_file($grammar_file); 
$grammar =~ s/\x0d\x0a/\n/g; 
$grammar =~ s/^\s+(?=[\w-]+\s*=)//mg; 

$grammar = Parse::ABNF->new->parse( scalar read_file($grammar_file)); 
if (defined $grammar) { 
    print "Grammar is now defined...\n"; 
    my $header; 
    open ($header , "<", $messages) or die "Could not open $messages file"; 
    while(<$header>) { 
     print "Processing the message $_\n"; 
     @header_name = split(': ', $_); 
     if ($header_name[0] eq "From") { 
      $header_status = $grammar->From($_) ; 
     } elsif ($header_name[0] eq "To") { 
      $header_status = $grammar->To($_) ; 
     } elsif ($header_name[0] eq "Contact") { 
      $header_status = $grammar->Contact($_) ; 
     } elsif ($header_name[0] eq "Allow") { 
      $header_status = $grammar->Allow($_) ; 
     } elsif ($header_name[0] eq "Accept") { 
      $header_status = $grammar->Accept($_) ; 
     } else { 
      print "Error: Unsupported header $header_name[0] received\n"; 
     } 
    } 
} else { 
     print "Error: grammar is not defined\n"; 
} 

的Perl invokation和输出/误差小于

$> perl -I. testSipHeader.pl sip.abnf recd_messages.txt 
Grammar is now defined... 
Processing the message From: <sip:07455900064@212.136.178.216:5060;user=phone>;tag=1526438727- 

Can't call method "From" on unblessed reference at testSipHeader.pl line 21, <$header> line 1. 

注：目前我有根儿的C程序吃了SIP头，我想通过这个Perl函数验证头的内容。我想使用类似用法在链接给Parse::RecDescent grammar not working as expected

我不得不修改一点点在你的脚本，包括解析:: ABNF和处理输入文件，之后接收的输出出现在路径https://drive.google.com/file/d/0B8KDQDXsCKR_ZERzV3IyY1M2NW8/edit?usp=sharing

Answer 1

我把你的脚本重写了一下，输出是什么？

use Data::Dumper; 
my $grammar_rules; 
{ 
    local $/=undef; 
    open(my $fh,'<',$grammar_file) or die $grammar_file,$!; 
    $grammar_rules = <$fh>; 
    $grammar_rules =~ s/\x0d\x0a/\n/g; 
    $grammar_rules =~ s/^\s+(?=[\w-]+\s*=)//mg; 
} 
print Dumper('rules',$grammar_rules); 
my $grammar = Parse::ABNF->new->parse( $grammar_rules); 
print Dumper('grammar',$grammar); 
die "Error: grammar is not defined" if ! defined $grammer; 
print "Grammar is now defined...\n"; 

open (my $header_fh , "<", $messages) or die "Could not open $messages file, $!"; 
while(my $line = <$header_fh>) { 
    chomp($line); 
    print "Processing the message $line\n"; 
    @header_name = split(': ', $line); 
    if ($header_name[0] eq "From") { 
     $header_status = $grammar->From($line) ; 
    } elsif ($header_name[0] eq "To") { 
     $header_status = $grammar->To($line) ; 
    } elsif ($header_name[0] eq "Contact") { 
     $header_status = $grammar->Contact($line) ; 
    } elsif ($header_name[0] eq "Allow") { 
     $header_status = $grammar->Allow($line) ; 
    } elsif ($header_name[0] eq "Accept") { 
     $header_status = $grammar->Accept($line) ; 
    } else { 
     print "Error: Unsupported header $header_name[0] received\n"; 
    } 
}