Question

我是初学者perl程序员。我有以下perl代码片段，无法理解为什么我不能将ascii字符（$ ascii_chr）打印到OUTFILE。当我打印到控制台时似乎工作正常。

无法理解为什么在下面的print语句

中没有将字符转储到OUTFILE

 print OUTFILE $ascii_chr;  ## But this print statement does not work.

以下是此特定循环的代码段。

#Now look for start_conversion = 1 and then convert the hex data into ascii data
if (($start_conversion == 1) && ($_ != '5f535452') && ($_ != '5f454e44'))  {
    chomp;
    $_ =~ s/000000/ 0x/g;
    @my_array = split(/ /, $_); 
    foreach $split_word(@my_array) {
        $ascii_chr = chr(hex($split_word));
        print $ascii_chr;       ## This print statement works.  
        print OUTFILE $ascii_chr;  ## But this print statement does not work.  
    }
}

这是完整的代码。我尝试了几件事，但永远不会打印到OUTFILE。

#!/usr/bin/perl
$num_arg = $#ARGV + 1;
if (($ARGV[0] =~ /help/)) {
 print "post_code_log.pl <inputfile> <outputfile> \n";
 exit;
}
$infile_name = $ARGV[0];
$outfile_name = $ARGV[1];

#Logic to remove non-ascii characters from a text file
$count            = 0;
$start_num        = '5f535452';
$stop_num         = '5f454e44';
$start_conversion = 0;
open (DATA,    "$infile_name");
open (OUTFILE, ">$outfile_name");
while (<DATA>) {
    s/^;.*//g;  # Remove a line starting with ;
    s/^\n//g;   # Remove blank lines
    s/.*?://;   # Remove first column 
    s/.*?Port80Wr//; # Remove the first column look for Port80Wr  
                     # (since the first column contains "Port80Wr")
    s/^\s+//g;  # Remove the space in front

    #Look for start signature
    if ($_ =~ '5f535452') {
        print $_;
        $start_conversion = 1;
    } 
    #Look for stop signature 
    if ($_ =~ '5f454e44') {
        print OUTFILE "\n";  # May need to print newline
        print $_;
        $start_conversion = 0;
    }
    # Now look for conversion start and then convert hex to ascii 
    if (($start_conversion == 1) && ($_ != '5f535452') && ($_ != '5f454e44')) {
        chomp;
        $_ =~ s/000000/ 0x/g;
        @my_array = split(/ /, $_); 
        foreach $split_word(@my_array) {
            $ascii_chr = chr(hex($split_word));
             print $ascii_chr;
             print OUTFILE $ascii_chr;
        }
    }
    # Now look for conversion end and send the data 
    # as is without making any changes
    if (($start_conversion == 0) && ($_ != '5f535452') && ($_ != '5f454e44')) {
        print OUTFILE $_;
    }
}
print "Done\n";

Answer 1

检查您的文件是否真的开放：

open (OUTFILE, ">", $outfile_name) or die "Cannot open '$outfile_name': $!";

还要在代码顶部附近添加：

use warnings;

无法使用perl打印输出文件

1 个答案: