Question

Is there a simple way to write to file the mercurial version (or similar external command) in a gradle task:

I’m not yet groovy/gradle conversant, but my current effort looks like this:

task versionInfo(type:Exec){
    commandLine 'hg id -i -b -t'
    ext.versionfile = new File('bin/$baseName-buildinfo.properties')

    doLast {
        versionfile.text = 'build.revision=' + standardOutput.toString()
    }
}

Answer 1

There are two issues with this build script:

1. the command line needs to be split; gradle’s trying to execute a binary named hg id -i -b t instead of hg with arguments id, -i, -b and t
2. The standard output needs to be captured; you can make it a ByteOutputStream to be read later

Try this:

task versionInfo(type:Exec){
    commandLine 'hg id -i -b -t'.split()
    ext.versionfile = new File('bin/$baseName-buildinfo.properties')
    standardOutput = new ByteArrayOutputStream()

    doLast {
        versionfile.text = 'build.revision=' + standardOutput.toString()
    }
}