Here is an update to the r&l scripts I posted about earlier. The new update finalized the Generate Batch Render Commands script. You can launch this script and choose various parameters from your scene and it will automatically generate the correct syntax to render via the command line. You can choose various settings in the fields and drop-downs, then press the 'Append Command' button to add the render command to the text area. You can change the values and press 'Append Command' again to generate multiple rendering jobs (for multiple render layers, resolutions or file formats for example). Then you can press 'Save Script' to save the file as a shell script to the data folder of your project directory. These commands work best when you have a project set for your scene in Maya. For more information on rendering via the command line check out this blog post.