Question

I use xmlstarlet el -v to display the structure of an xml file, including all the attributes and values. I would like to convert its output to some sort of key-value pairs, i.e. each attribute with its value on a separate line (including the XPath); each line must be unique.

<?xml version=1.0 encoding=UTF-8?>
<topRoot>
  <topSystem>
    <commSvcEp>
      <commSyslog descr="Syslog Service" name="syslog" policyOwner="local" severity="critical">
        <commSyslogClient adminState="disabled" forwardingFacility="local7" hostname="none" name="secondary" severity="critical"></commSyslogClient>
        <commSyslogClient adminState="disabled" forwardingFacility="local7" hostname="none" name="tertiary" severity="critical"></commSyslogClient>
        <commSyslogClient adminState="disabled" forwardingFacility="local7" hostname="none" name="primary" severity="critical"></commSyslogClient>
      </commSyslog>
    </commSvcEp>
  </topSystem>
</topRoot>

Current result:

topRoot/topSystem/commSvcEp/commSyslog[@descr='Syslog Service' and @name='syslog' and @policyOwner='local' and @severity='critical']
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[@adminState='disabled' and @forwardingFacility='local7' and @hostname='none' and @name='secondary' and @severity='critical']
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[@adminState='disabled' and @forwardingFacility='local7' and @hostname='none' and @name='tertiary' and @severity='critical']
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[@adminState='disabled' and @forwardingFacility='local7' and @hostname='none' and @name='primary' and @severity='critical']

Desired result (could be anything similar; the indices are just an idea):

topRoot/topSystem/commSvcEp/commSyslog@descr='Syslog Service'
topRoot/topSystem/commSvcEp/commSyslog@name='syslog'
topRoot/topSystem/commSvcEp/commSyslog@policyOwner='local'
topRoot/topSystem/commSvcEp/commSyslog@severity='critical'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[0]@adminState='disabled'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[0]@forwardingFacility='local7'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[0]@hostname='none'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[0]@name='secondary'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[0]@severity='critical'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[1]@adminState='disabled'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[1]@forwardingFacility='local7'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[1]@hostname='none'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[1]@name='tertiary'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[1]@severity='critical'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[2]@adminState='disabled'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[2]@forwardingFacility='local7'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[2]@hostname='none'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[2]@name='primary'
topRoot/topSystem/commSvcEp/commSyslog/commSyslogClient[2]@severity='critical'

What I’m trying to accomplish, is being able to run diff over two such files or using grep to filter matching patterns. I’m sure there’s a way to create such output, without using sed, awk or anything else but xmlstarlet itself.

I’m pretty much a newbie regarding xmlstarlet and the whole xml world (not only by the fact that I dislike xml due to its complexity and parsing overhead, etc), so I’d really appreciate your help. Thanks!

Answer 1

Since you’re already using xmlstarlet, you could also use XSLT.

XSLT 1.0 (can be run with xmlstarlet by using the tr command)

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="text"/>
    <xsl:strip-space elements="*"/>

    <xsl:param name="sep" select="'.'"/>

    <xsl:template match="text()"/>

    <xsl:template match="*">
        <xsl:variable name="path">
            <xsl:for-each select="ancestor-or-self::*">
                <xsl:variable name="predicate">
                    <xsl:call-template name="genPredicate"/>
                </xsl:variable>
                <xsl:if test="ancestor::*">
                    <xsl:value-of select="$sep"/>
                </xsl:if>
                <xsl:value-of select="concat(local-name(),$predicate)"/>
            </xsl:for-each>
        </xsl:variable>
        <xsl:for-each select="@*">
            <xsl:value-of select="concat($path,$sep,name(),'=',.)"/>
            <xsl:text>&#xA;</xsl:text>
        </xsl:for-each>
        <xsl:if test="not(@*)">
            <xsl:text>&#xA;</xsl:text>          
        </xsl:if>
        <xsl:apply-templates select="node()"/>
    </xsl:template>

    <xsl:template name="genPredicate">
        <xsl:if test="preceding-sibling::*[local-name()=local-name(current())] or following-sibling::*[local-name()=local-name(current())]">
            <xsl:value-of select="concat('[',count(preceding-sibling::*[local-name()=local-name(current())])+1,']')"/>          
        </xsl:if>
    </xsl:template>

</xsl:stylesheet>

Note: There is a parameter named sep so you can change the separator from the command line (using -p sep="/" or whatever separator you want). It’s currently set to your preferred “.”.

Output

commSyslog.descr=Syslog Service
commSyslog.name=syslog
commSyslog.policyOwner=local
commSyslog.severity=critical
commSyslog.commSyslogClient[1].adminState=disabled
commSyslog.commSyslogClient[1].forwardingFacility=local7
commSyslog.commSyslogClient[1].hostname=none
commSyslog.commSyslogClient[1].name=secondary
commSyslog.commSyslogClient[1].severity=critical
commSyslog.commSyslogClient[2].adminState=disabled
commSyslog.commSyslogClient[2].forwardingFacility=local7
commSyslog.commSyslogClient[2].hostname=none
commSyslog.commSyslogClient[2].name=tertiary
commSyslog.commSyslogClient[2].severity=critical
commSyslog.commSyslogClient[3].adminState=disabled
commSyslog.commSyslogClient[3].forwardingFacility=local7
commSyslog.commSyslogClient[3].hostname=none
commSyslog.commSyslogClient[3].name=primary
commSyslog.commSyslogClient[3].severity=critical
commSyslog.commSyslogMonitor.adminState=disabled
commSyslog.commSyslogMonitor.descr=
commSyslog.commSyslogMonitor.name=
commSyslog.commSyslogMonitor.severity=critical
commSyslog.commSyslogConsole.adminState=disabled
commSyslog.commSyslogConsole.descr=
commSyslog.commSyslogConsole.name=
commSyslog.commSyslogConsole.severity=critical
commSyslog.commSyslogSource.audits=disabled
commSyslog.commSyslogSource.descr=
commSyslog.commSyslogSource.events=disabled
commSyslog.commSyslogSource.faults=enabled
commSyslog.commSyslogSource.name=
commSyslog.commSyslogFile.adminState=enabled
commSyslog.commSyslogFile.descr=
commSyslog.commSyslogFile.name=messages
commSyslog.commSyslogFile.severity=critical
commSyslog.commSyslogFile.size=4194304