Final answer:
The command to set limits on file size in Unix-based systems is 'ulimit', specifically with the '-f' option for file sizes.When you execute the ulimit command with appropriate options, you can control the resources available to the shell and to processes started by the shell.
Step-by-step explanation:
The command used to set limits on file size in Unix-based systems is ulimit. When you execute the ulimit command with appropriate options, you can control the resources available to the shell and to processes started by the shell. To specifically limit file size, the ulimit -f option is used, with the size to be set expressed in blocks.