xslt examples for https://github.com/halfwit/scripts/blob/master/updatefeeds, full credit to @Earnestly

feed.xslt

<xsl:stylesheet version="1.0"
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:atom="http://www.w3.org/2005/Atom">
    <xsl:output method="text"/>
    <xsl:template match="/atom:feed">
        <xsl:for-each select="atom:entry">
            <xsl:value-of select="atom:link/@href"/>
            <xsl:text>&#x9;</xsl:text>
            <xsl:value-of select="atom:title"/>
            <xsl:text>&#10;</xsl:text>
        </xsl:for-each>
	</xsl:template>
</xsl:stylesheet>

rdf.xslt

<xsl:stylesheet version="1.0"
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:rss="http://purl.org/rss/1.0/"
    xmlns:dc="http://purl.org/dc/elements/1.1/"
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
    <xsl:output method="text"/>
    <xsl:template match="/rdf:RDF">
        <xsl:for-each select="rss:item">
            <xsl:value-of select="rss:link"/>
            <xsl:text>&#x9;</xsl:text>
            <xsl:value-of select="rss:title"/>
            <xsl:text>&#10;</xsl:text>
        </xsl:for-each>
    </xsl:template>
</xsl:stylesheet>

rss.xslt

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="text"/>
    <xsl:template match="/rss">
        <xsl:for-each select="channel/item">
            <xsl:choose>
                <xsl:when test="guid/@isPermaLink = 'true'">
                    <xsl:value-of select="guid"/>
                </xsl:when>
                <xsl:otherwise>
                    <xsl:value-of select="link"/>
                </xsl:otherwise>
            </xsl:choose>
            <xsl:text>&#x9;</xsl:text>
            <xsl:value-of select="title"/>
            <xsl:text>&#10;</xsl:text>
        </xsl:for-each>
    </xsl:template>
</xsl:stylesheet>