$
$
$ cat sample.xml
<?xml version="1.0"?>
<catalog>
   <book id="bk101">
      <author>Gambardella, Matthew</author>
      <title>XML Developer's Guide</title>
      <genre>Computer</genre>
      <price>44.95</price>
      <publish_date>2000-10-01</publish_date>
      <description>An in-depth look at creating applications with XML.</description>
   </book>
   <book id="bk102">
      <author>Ralls, Kim</author>
      <title>Midnight Rain</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2000-12-16</publish_date>
      <description>A former architect battles corporate zombies,
      an evil sorceress, and her own childhood to become queen
      of the world.</description>
   </book>
   <book id="bk103">
      <author>Corets, Eva</author>
      <title>Maeve Ascendant</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2000-11-17</publish_date>
      <description>After the collapse of a nanotechnology
      society in England, the young survivors lay the
      foundation for a new society.</description>
   </book>
   <book id="bk104">
      <author>Corets, Eva</author>
      <title>Oberon's Legacy</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2001-03-10</publish_date>
      <description>In post-apocalypse England, the mysterious
      agent known only as Oberon helps to create a new life
      for the inhabitants of London. Sequel to Maeve
      Ascendant.</description>
   </book>
   <book id="bk105">
      <author>Corets, Eva</author>
      <title>The Sundered Grail</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2001-09-10</publish_date>
      <description>The two daughters of Maeve, half-sisters,
      battle one another for control of England. Sequel to
      Oberon's Legacy.</description>
   </book>
</catalog>
$
$

$
$ perl -lne 'BEGIN{undef $/} while (/<description>(.*?)<\/description>/sg){print $1}' sample.xml
An in-depth look at creating applications with XML.
A former architect battles corporate zombies,
      an evil sorceress, and her own childhood to become queen
      of the world.
After the collapse of a nanotechnology
      society in England, the young survivors lay the
      foundation for a new society.
In post-apocalypse England, the mysterious
      agent known only as Oberon helps to create a new life
      for the inhabitants of London. Sequel to Maeve
      Ascendant.
The two daughters of Maeve, half-sisters,
      battle one another for control of England. Sequel to
      Oberon's Legacy.
$
$

$
$ perl -lne 'BEGIN{undef $/} while (/<description>(.*?)<\/description>/sg){($x = $1) =~ s/\n\s*/\n/g; print $x}' sample.xml
An in-depth look at creating applications with XML.
A former architect battles corporate zombies,
an evil sorceress, and her own childhood to become queen
of the world.
After the collapse of a nanotechnology
society in England, the young survivors lay the
foundation for a new society.
In post-apocalypse England, the mysterious
agent known only as Oberon helps to create a new life
for the inhabitants of London. Sequel to Maeve
Ascendant.
The two daughters of Maeve, half-sisters,
battle one another for control of England. Sequel to
Oberon's Legacy.
$
$

$
$ perl -lne 'BEGIN{undef $/} while (/<description>(.*?)<\/description>/sg){($x = $1) =~ s/\n\s*//g; print $x}' sample.xml
An in-depth look at creating applications with XML.
A former architect battles corporate zombies, an evil sorceress, and her own childhood to become queen of the world.
After the collapse of a nanotechnology society in England, the young survivors lay the foundation for a new society.
In post-apocalypse England, the mysterious agent known only as Oberon helps to create a new life for the inhabitants of London. Sequel to Maeve Ascendant.
The two daughters of Maeve, half-sisters, battle one another for control of England. Sequel to Oberon's Legacy.
$
$