perl - How to split in blocks a file and count the intermediate lines -

i have file this:

fixedstep chrom=chr22 start=14430001 step=1 144300010.000 0.002 0.030 0.990 0.000 0.000 0.000 fixedstep chrom=chr22 start=14430001 step=1 0.000 0.000 0.000 

and take number of start every line starts fixedstep , put counter in every of other lines. eg.

fixedstep chrom=chr22 start=14430001 step=1 14430001   0.000 14430002   0.002 14430003   0.030 fixedstep chrom=chr22 start=16730005 step=1 16730005   0.990 16730006   0.000 ......... 

i wrote code doesn't work.

open $scores_info, $scores_file or die "could not open $scores_file: $!"; while( $sline = <$scores_info>)  {      if ($sline=~ m/fixedstep/) {         @data = split(' ', $sline);         @begin = split('=', $data[2]);         $start = $begin[1];         print "$start\n";         $nextline = <$scores_info>;         $start++;         print $start . "\t" .  $nextline;     } 

an print in new file. me please?? thank in advance

if encounter line "fixedstep", set $count , print line. otherwise, print , increment $count:

my $count = 0; while( $sline = <$scores_info>)  {      if ($sline=~ m/fixedstep/) {         @data = split(' ', $sline);         @begin = split('=', $data[2]);         $count = $begin[1];         print $sline;     } else {         print $count++ . "\t" . $sline;     } } 

output:

fixedstep chrom=chr22 start=14430001 step=1 14430001    144300010.000 14430002    0.002 14430003    0.030 14430004    0.990 14430005    0.000 14430006    0.000 14430007    0.000 fixedstep chrom=chr22 start=16730005 step=1 16730005    0.990 16730006    0.000 16730007    0.000