use warnings; use strict; my @path; my @data; my $size = 0; while() { chomp; $path[0] = $1 if /^([^|]*)$/; $path[length($1)/3] = $2 if /^(.*\|--)([^-]+)$/; if( /^(.*\|--)-([^-]+)$/ ) { $#path = length($1)/3 - 1; push @data, [ @path, $2 ]; $size = @path if $size < @path; } } splice @$_, -1, 0, ('')x(1+$size-@$_) for @data; print join( "\t", @$_ ),"\n" for @data; __DATA__ A | |--B | | | |--C | | | |---PQR | |---XYZ |--D | | | |---LMN |---XYZ