在下面，您可以找到我正在编写的脚本。我的问题在脚本下面。

use XML::Writer; 
use IO; 
 
@sortedPLATFORMS = qw(win32_x86 win64_x64 linux_x86 linux_x64 solaris_sparc solaris_sparcv9 aix_rs6000 aix_rs6000_64 hpux_pa-risc hpux_ia64); 
@STARTS = qw(wdf_22_00 wdf_23_00 wdf_00_00 wdf_01_00 wdf_02_00); 
 
my @waitFors; 
 
my $thisPlatform; 
my $thisMachine; 
my $thisTask; 
my $thisBuild; 
my $thisCMD; 
my $thisWaitFor; 
 
 
foreach my $start(@STARTS) 
{    
    my $jobFile = "jobs/$start.txt"; 
    my $doc = new IO::File(">$start.xml", 'w'); 
    my $writer = new XML::Writer(OUTPUT => $doc) or die "Cannot open file"; 
    $writer->xmlDecl("UTF-8"); #XML declaration 
    $writer->startTag("$start"); 
 
    if(open(JOB_FILE,$jobFile)) 
    { 
    while(<JOB_FILE>) 
    { 
        chomp; 
        s-^\s+$--; 
        next unless($_); 
        next if(/^\;/); 
        next if(/\[config\]/); 
        next if(/event_dir\s+\=\s+(.+?)$/); 
 
        if(/\[(.+?)\]/) 
        { 
            getInfos(); 
        } 
        elsif(/^\s+waitfor\s+\=\s+(.+?)$/) 
        { 
            $thisWaitFor = $1; 
            push(@waitFors, "$thisWaitFor"); 
        } 
        elsif(/^\s+command\s+\=\s+(.+?)$/) 
        { 
            $thisCMD = $1; 
            writeXML(); 
            @waitFors = (); 
        }        
    } 
} 
else 
{ 
    print "something is wrong"; 
} 
 
$writer->endTag(); 
    $writer->end(); 
    $doc->close(); 
close JOB_FILE; 
} 

    Can't call method "characters" on an undefined value at createMachineList.pl 
 line 96, <JOB_FILE> line 13. 

请您参考如下方法:

您在循环内声明了my $writer。该函数在循环外部声明。因此，该函数无法访问该变量。要么将其作为参数传递，要么将其设为全局(不推荐)。您正在使用strict和warnings吗？