If you want to collect data for all descendant processes that are followed by the Collector, you must use the collect command with one of the following options:
-F on option enables you to collect data automatically for calls to fork and its variants and exec and its variants, and all other descendant processes, including those due to calls to system, popen, posix_spawn(3p), posix_spawnp(3p), and sh
-F all is the same as -F on.
–F '=regexp' option enables data to be collected on all descendant processes whose name matches the specified regular expression.
See Experiment Control Options for more information about the –F option.