Bash Parse XML to Array

Question

I am doing a mixed language script with the parent script being bash (don't ask why, it's a long story). Part of my script pulls the source of an XML page into a variable. I want to use bash to process the XML in the variable into several arrays. The XML is set up as follows:

<event>
    <id>34287352</id>
    <what>New Post</what>
    <when>1 Minute Ago 03:50 PM</when>
    <title>This is a title</title>
    <preview>sdfasd</preview>
    <poster>
            <![CDATA[ USERNAME ]]>
    </poster>
    <threadid>2346566</threadid>
    <postid>34287352</postid>
    <lastpost>1360021837</lastpost>
    <userid>3291696</userid>
    <forumid>2</forumid>
    <forumname>General Discussion</forumname>
    <views>201,913</views>
    <replies>6,709</replies>
    <statusicon>images/statusicon/thread.gif</statusicon>
</event>

There are 20 <event>'s in the XML file. I want to pull what title and preview from the XML and put them all into their own array

I followed an example here on SOF

for tag in  what title preview 
do
OUT=`grep  $tag $source | tr -d '\t' | sed 's/^<.*>\([^<].*\)<.*>$/\1/' `

# This is what I call the eval_trick, difficult to explain in words.
eval ${tag}=`echo -ne \""${OUT}"\"`
done

W_ARRAY=( `echo ${what}` )
T_ARRAY=( `echo ${title}` )
P_ARRAY=( `echo ${preview}` )

echo ${W_ARRAY[0]}
echo ${T_ARRAY[0]}
echo ${P_ARRAY[0]}

But using the above my script always freaks right out and repeats grep: <part of the xml>: No such file or directory

Thoughts?

EDIT:

Well it is ugly as hell but I managed to get the sudoxml into an array

windex=0
tindex=0
pindex=0
while read -r line
do
WHAT=$(echo ${line} | awk -F "</?what>" '{ print $2 }')
if [ "$WHAT" != "" ]; then
    W_ARRAY[$windex]=$OUT
    let windex+=1
fi
TITLE=$(echo ${line} | awk -F "</?title>" '{ print $2 }')
if [ "$TITLE" != "" ]; then
    T_ARRAY[$tindex]=$OUT
    let tindex+=1
fi
PREVIEW=$(echo ${line} | awk -F "</?preview>" '{ print $2 }')
if [ "$PREVIEW" != "" ]; then
    P_ARRAY[$pindex]=$OUT
    let pindex+=1
fi
done <<< "$source"

Answer 1

I had something sooo similar, parsing wise, here's a hacked version

I use xsltproc (which is in ubuntu, but can't remember if I have installed it specifically)

Command line

xsltproc tfile.xslt tfile.xml

tfile.xml (is your example copied 3 times), wrapped in events tags ie.

<events>
     <event> ... </event>
     <event> ... </event>
     <event> ... </event>
</events>

tfile.xsl :

<?xml version='1.0'?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">

<xsl:output method='text'/>
<!-- ================================================================== -->
<xsl:template match="/">
    <xsl:apply-templates select="//event"/>
</xsl:template>

<xsl:template match="event">
 <xsl:text>event[</xsl:text><xsl:value-of select="position()"/><xsl:text>]['id']=</xsl:text>
 <xsl:value-of select="id"/> <xsl:text> </xsl:text>

 <xsl:text>event[</xsl:text><xsl:value-of select="position()"/><xsl:text>]['what']=</xsl:text>
 <xsl:value-of select="what"/><xsl:text> </xsl:text>

 <xsl:text>event[</xsl:text><xsl:value-of select="position()"/><xsl:text>]['preview']=</xsl:text>
 <xsl:value-of select="preview"/><xsl:text> </xsl:text>

 <xsl:text>
</xsl:text>
</xsl:template>

</xsl:stylesheet>

Output

event[1]['id']=34287352 event[1]['what']=New Post event[1]['preview']=sdfasd 
event[2]['id']=34287353 event[2]['what']=New Post3 event[2]['preview']=sdfasd 
event[3]['id']=34287354 event[3]['what']=New Post4 event[3]['preview']=sdfasd

Hope you know a bit of xslt processing, change output as you want.