Prints out the version numbers of DejaGnu, expect and Tcl, and exits without running any tests. The Tcl debugger supports breakpoints, single stepping, and other common debugging activities. Specify the names of testsuites to run. By default, runtest runs all tests for the tool, but you can restrict it to particular testsuites by giving the names of the .exp expect scripts that control them. For compiler or assembler tests, which often use a single .exp script covering many different source files, this option allows you to further restrict the tests by listing particular source files to compile.
Some tools even support wildcards here.
Typically, you don't need must to use any command-line options. By default, runtest prints only the names of the tests it runs, output from any tests that have unexpected results, and a summary showing how many tests passed and how many failed. The files DejaGnu produces.