How can I get the value from an attribute using xmllint and XPath?

xml shell xpath

61,048

Solution 1

You need to use fn:string(), which will return the value of its argument as xs:string. In case its argument is an attribute, it will therefore return the attribute's value as xs:string.

test=$(xmllint --xpath "string(//body/value/@name)" test.xml)

Solution 2

Try this, it's not beautiful but it works :)

I just erase lines containing > from stdout , cut the string to get the second part after the = , and delete "

test=$(echo 'cat //body/value/@name' | xmllint --shell "test.xml" | grep -v ">" | cut -f 2 -d "=" | tr -d \"); 
echo $test

Solution 3

An approach with a helper awk command that supports multiple attributes (a streamlined version of ego's approach):

echo 'cat //*/@name' | xmllint --shell file | awk -F\" 'NR % 2 == 0 { print $2 }'

The awk command:

splits xmllint's output lines into fields by " chars. (-F\")
- Note that xmllint normalizes quoting around attribute values to "..." on output, even if the input had '...', so it's sufficient to split by ".
only processes even-numbered lines (NR %2 == 0), thereby filtering out the separator lines that cat invariably prints.
print $2 then prints only the 2nd field, which is the value of each attribute without the enclosing "...".

Assuming the following sample XML in file:

<body>
  <value name="abc"></value>
  <value name="def"></value>
</body>

the above yields:

abc
def

Solution 4

I recently had to port my original simpler solution using --xpath to a platform lacking this feature, so had to adopt the "cat" solution too. This will handle multiple matches, tested on Ubuntu 12.04 and Solaris 11:

getxml() { # $1 = xml file, $2 = xpath expression
    echo "cat $2" | xmllint --shell $1 |\
    sed -n 's/[^\"]*\"\([^\"]*\)\"[^\"]*/\1/gp'
}

e.g. extracting instance names from a glassfish domain config:

$ getxml /tmp/test.xml "//server[@node-ref]/@name"
inst1
inst2

The sed post-processing just grabs all quoted values which was adequate for my needs (getting bits of glassfish config).

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61,048

Author by

Tran Ngu Dang

Geek forever !!!

Updated on November 05, 2021

Comments

Tran Ngu Dang over 2 years
I want to get the value of name and put it in a variable using XMLLint
```
<body>
<value name="abc"></value>
</body>

echo 'cat //body/value/@name' | xmllint --shell "test.xml"

/ >  -------
 name="abc"
/ > 
```
So I want to assign the value "abc" to variable $test
Fergie over 11 years

unfortunately --xpath is unsupported on a lot of installations
badp about 9 years

Use xmllint so you don't have to use REs to parse XML. Realize you have to use REs to parse the output of xmllint.
Ciro Santilli OurBigBook.com over 8 years

This only shows the value for a single element, is it possible to get multiple matches?
आनंद over 7 years

why does it print ------- before the name attribute value? how to remove it?
dieHellste over 6 years

this works perfectly for me, thanks. Do you also have a nice way of assigning the values to different variables. Like VAR_1=$(echo 'cat //*/@name' | xmllint --shell file | awk -F\" 'NR % 2 == 0 { print $2 }') ?
mklement0 over 6 years

@dieHellste: You can read the output lines into variables (either in a while loop or, in Bash, into an array with read -a); if you need further guidance, please ask a new question.
MariusMatutiae almost 4 years

@CiroSantilli郝海东冠状病六四事件法轮功 You can get multiple matches with xmllint --xpath "//body/value/@name", but they will be all on the same line, unless you have version 2.9.9 or newer of the package libmxl2-utils.