function allocate next batch id in 'raw' format
= NAME = allocate_next_batch_id = SYNOPSIS = Allocate and return the next global batch id for the Fuego system. = DESCRIPTION = This function reads the global batch_id file for Fuego, and returns it. It then increments the number and saves it back to the file for the next allocation operation. The global batch_id is stored in $FUEGO_RW/logs/next_batch_id, and is global over all tests. Using this function will make the batch_id a monotonically increasing decimal number. Callers of this function are encouraged to use this global number for batch tests, but to also prefix the number with a test-specific string, so that batch_ids are easier for humans to associate with their related batch tests. = EXAMPLES = Here are some sample invocations: {{{#!YellowBox FUEGO_BATCH_ID="prefix-$(allocate_next_batch_id)" }}} = ENVIRONMENT and ARGUMENTS = Environment variables used: * FUEGO_RW = RETURN = Returns non-zero on error. = SOURCE = Located in ''scripts/functions.sh'' = SEE ALSO = * [[Using Batch Tests]], [[function_run_test|run_test]]