Build:

xcodebuild -exportArchive -exportFormat ipa \\
    -archivePath "/Users/username/Desktop/MyiOSApp.xcarchive" \\
    -exportPath "/Users/username/Desktop/MyiOSApp.ipa" \\
    -exportProvisioningProfile "MyCompany Distribution Profile"

Archive:

xcodebuild -project <ProjectName.xcodeproj> 
    -scheme <ProjectName> 
    -sdk iphonesimulator 
    -configuration Debug 
    -destination "platform=iOS Simulator,name=<Device>,OS=9.3" 
    clean build