bash XHTML parsing using xpath - bash

Question

I'm writing a small script to learn how to parse an XHTML web page. The following command:
cat q?s=goog.xhtml | xpath '//span[#id="yfs_l10_goog"]'
returns:
Found 2 nodes:
-- NODE --
<span id="yfs_l10_goog">624.50</span>-- NODE --
<span id="yfs_l10_goog">624.50</span>
How do I:
need to write my command in order to only extract the value 624.50 ?
what do I need to do to extract it only once ?
source page I'm parsing: http://finance.yahoo.com/q?s=goog

Answer 1

Edit 2:
Give this a try:
xpath -q -e '//span[#id="yfs_l10_goog"][1]/text()'
Edit:
Pipe your output through:
sed -n '/span/{s/<span[^<]*>\([^<]*\)<.*/\1/;p;q}'
Original answer:
Using xmlstarlet:
echo -e '<foo><span id="yfs_l10_goog">624.50</span>\n<bar>xyz</bar><span id="yfs_l10_goog">555.50</span>\n<span id="yfs_l10_goog">123.50</span></foo>' |
xmlstarlet sel -t -v "//span[#id='yfs_l10_goog']"
Result of query:
624.50
Result of echo:
<foo><span id="yfs_l10_goog">624.50</span>
<bar>xyz</bar><span id="yfs_l10_goog">555.50</span>
<span id="yfs_l10_goog">123.50</span></foo>
Result of xml fo:
<?xml version="1.0"?>
<foo>
<span id="yfs_l10_goog">624.50</span>
<bar>xyz</bar>
<span id="yfs_l10_goog">555.50</span>
<span id="yfs_l10_goog">123.50</span>
</foo>
Other queries:
$ echo -e '...' | xmlstarlet sel -t -v "//span[#id='yfs_l10_goog'][1]"
624.50
$ echo -e '...' | xmlstarlet sel -t -v "//span[#id='yfs_l10_goog'][3]"
123.50
$ echo -e '...' | xmlstarlet sel -t -v "//span[#id='yfs_l10_goog'][last()]"
123.50