Prints address map with gap size between segment within a core file

CoreAmap.scala

/**
 * Prints address map with gap size between segment
 * within a core file.  This program uses readelf
 * command and expects the output is same as the 
 * readelf on Linux.
 */
object CoreAmap {
  def main(args: Array[String]) {
    for (a <- args) doAmapCore(a)
  }
  def extractPhdrs(input: String) = {
    val lns = input.split("\\n").toList
    lns.dropWhile(! _.startsWith("Program Headers:")).
        drop(1).takeWhile(_.length > 0).map(_.trim).
        filter(_.startsWith("LOAD")).
        map(_.split("\\s+")).
        map(e => Seg(hexToLong(e(2)), hexToLong(e(5))))
  }
  case class Seg(va: Long, sz: Long) {
    require(sz > 0)
    val end = va + sz
    override def toString = 
        "[0x%x, 0x%x), sz 0x%x".format(va, end, sz)
  }
  def hexToLong(str: String) = {
    val ts = "^0[xX][0-9a-fA-F]+".r.findFirstIn(str) match {
      case Some(s) => str.drop(2)
      case None    => str
    }
    java.lang.Long.parseLong(ts, 16)
  }
  
  def doAmapCore(path: String) {
    import scala.sys.process._
    val phdrs = extractPhdrs(Process("readelf -l " + path) !!)
    def doAna(segs: List[Seg], prev: Option[Seg]) : List[String] = {
      segs match {
        case Nil => List("")
        case x::xs => {
          prev match {
            case None => x.toString :: doAna(xs, Some(x))
            case Some(ps) => {
              (x.va - ps.end) match {
                case 0 => x.toString :: doAna(xs, Some(x))
                case diff if diff > 0 => 
                    "  <<< GAP %dk >>>\n%s".
                        format(diff/1024L, x.toString) :: 
                      doAna(xs, Some(x))
                case diff => 
                    "E: unexpected diff %d".format(diff) :: 
                      doAna(xs, Some(x))
              }
            } // Some(ps)
          } // prev match
        } // x::xs
      } // segs match
    }
    println(doAna(phdrs, None).mkString("\n"))
  }
}