my $oneline = <$FL> 或 while（$line=<H>） { }

open (my $in, "path ") or die "open error: $! "; my @lines = <$in> ;

open (my $in, "path ") or die "open error: $! "; my @lines; push (@lines, scalar <$in> ) for (1..3);

while (<TEST>) {     if(index ($_, "=") > -1){        my $position=tell(TEST);        my $keyword_line=$_;        my $line_1=<TEST>;        my $line_2=<TEST>;     # @a=split//,$keyword_line;  比较它们的元素是否相等，一直没成功     # @b=split//,$line_1;         利用if ($a[0]eq $a[0])来判断     # @c=split//,$line_2;          if (($line_2)&&(index($line_2, "=")>-1)){ # 或者if ($line_2=~/=/)             print OUTFILE "$_$line_1";           }     if (!($line_2)) { print OUTFILE "$_$line_1"; last; }     seek(TEST, $position, 0);       }   }