linux xmllint schema validation fails but error code 0

Question

Command line xmllint --schema validation fails but $? returns 0

myinput.xml:

<myinput><header>mytestvalue</header></myinput>

myschema.xsd

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    <xsd:element name="myinput" type="xsd:string"/>
</xsd:schema>

Command:

$xmllint --schema myschema.xsd myinput.xml

Result:

Element myinput: child header should not be present
myinput.xml fails to validate

Command:

$echo $?

Result:

0

Could someone tell me why xmllint schema validation failure is not returned as an error? Or suggest me ways to capture this as an error in my shell script? In my shell script, current I am validating the above xmllint command in an "if" block and it fails only for xml well-formedness but succeeds for schema validation failure.

if the above is not returned as error, should I go about doing the ugly way of "grep fails" on the xmllint output to figure-out if schema validation succeeded or failed? Any thoughts?

Answer 1

There doesn't seem to be any better way other than the "AWK"ward way that I mentioned in my question. Anyways, here is how, I am working around:

$xmllint --noout --schema myschema.xsd myinput.xml >> $tmpFile
schemaResult=$(cat $tmpFile | grep myinput.xml | awk '{ print $2 }')
if [ "x$schemaResult" = "xvalidates" ];
    echo "Schema validation succeeded"
else
    echo "Schema validation failed"
fi