在bash中解析pom.xml中的版本

Question

Here is a snippet from my shell script -

regex="<version>([0-9]*)\.([0-9]*)\.([0-9]*)([^<]*)<\/version>.*"

#some unrelated lines of code

    echo $(grep -m 1 "<version>" $1)
    if [[ $(grep -m 1 "<version>" $1) =~ $regex ]]
    then
        main_version = "${BASH_REMATCH[1]}"
        feature_version = "${BASH_REMATCH[2]}"
        patch_version = "${BASH_REMATCH[3]}"
        tag = "${BASH_REMATCH[4]}"
    else
        echo "$1: Version not Found" >&2
    fi

But it is showing me the following output -

<version>1.1.7-release</version> <!-- ABC version -->
abc/xyz/pom.xml: Version not Found

But according to my understanding, regex should match with the output of grep (i echoed it to terminal for better clarity). So can someone tell what am i doing wrong?

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.company.abc</groupId>
    <artifactId>abc</artifactId>
    <version>1.1.7-release</version> <!-- abc version -->
</project>

Answer 1

Using XMLStarlet :

regex='^([0-9]*)[.]([0-9]*)[.]([0-9]*)(.*)'
version=$(xmlstarlet sel -N mvn='http://maven.apache.org/POM/4.0.0' \
                         -t -m '/mvn:project/mvn:version' -v . -n <pom.xml)

if [[ $version =~ $regex ]]; then
    main_version="${BASH_REMATCH[1]}"
    feature_version="${BASH_REMATCH[2]}"
    patch_version="${BASH_REMATCH[3]}"
    tag="${BASH_REMATCH[4]}"
    declare -p main_version feature_version patch_version tag
else
    echo "Could not extract or parse version tag" >&2
fi

...properly emits as output, given your pom.xml :

declare -- main_version="1"
declare -- feature_version="1"
declare -- patch_version="7"
declare -- tag="-release"