Perl 打印特定行日志

#!/usr/bin/perl $dir='/home/websphere/WebSphere/AppServer/profiles/AppSrv01/logs/server1';$file = 'SystemErr.log';$mon_file="$dir/$file";print "\$mon_file is $mon_file\n";@warn_arr = qw/连接已关闭 NullPointException IndexOutOfBound/;foreach $a  (@warn_arr){   open (C,"<","$a.tmp")  ;         while (<C>){                          $count  = $_;                                                }            print "\$count is $count\n";                                                                                                  $info =`tac $mon_file  |  grep "$a" | head -1`;                                                                                                                                  open (A ,"<","$mon_file") || die "$!\n";   $i=0;while (<A>) {          $num++;        if ($_ =~ /$a/i){$i++;$b=$num};       };         if ( $i !=0 && $i != $count && defined($count)) {    open (B ,"<","$mon_file") || die "$!\n";   while  (<B>) {  print $_  if ($.>=$b and $.<=$b + 10) }};                                                                                                                                                                                            open (C,">","$a.tmp");                                                                                                                                                                                             print C ("$i\n");                                                                                                                                                                                              }