-F option

Control whether or not descendant processes should have their data recorded. The allowed values of option are:

• on– Record experiments only on descendant processes that are created by functions fork, exec, and their variants.

• all– Record experiments on all descendant processes.

• off– Do not record experiments on descendant processes.

• = regexp– Record experiments on all descendant processes whose name or lineage matches the specified regular expression.

If you specify the -F on option, the Collector follows processes created by calls to the functions fork(2), fork1(2), fork(3F), vfork(2), and exec(2) and its variants. The call to vfork is replaced internally by a call to fork1.

If you specify the -F all option, the Collector follows all descendant processes including those created by calls to system(3C), system(3F), sh(3F), and popen(3C), and similar functions, and their associated descendant processes.

If you specify the -F '= regexp' option, the Collector follows all descendant processes whose name or lineage matches the specified regular expression. See the regexp(5) man page for information about regular expressions.

When you collect data on descendant processes, the Collector opens a new experiment for each descendant process inside the founder experiment. These new experiments are named by adding an underscore, a letter, and a number to the experiment suffix, as follows:

• The letter is either an “f” to indicate a fork, an “x” to indicate an exec, or “c” to indicate any other descendant process.

• The number is the index of the fork or exec (whether successful or not) or other call.

For example, if the experiment name for the initial process is test.1.er , the experiment for the child process created by its third fork is test.1.er/_f3.er. If that child process execs a new image, the corresponding experiment name is test.1.er/_f3_x1.er. If that child creates another process using a popen call, the experiment name is test.1.er/_f3_x1_c1.er.

The Analyzer and the er_print utility automatically read experiments for descendant processes when the founder experiment is read, but the experiments for the descendant processes are not selected for data display.

To select the data for display from the command line, specify the path name explicitly to either er_print or analyzer. The specified path must include the founder experiment name, and descendant experiment name inside the founder directory.

For example, here’s what you specify to see the data for the third fork of the test.1.er experiment:

er_print test.1.er/_f3.er

analyzer test.1.er/_f3.er

Alternatively, you can prepare an experiment group file with the explicit names of the descendant experiments in which you are interested.

To examine descendant processes in the Analyzer, load the founder experiment and select Filter Data from the View menu. A list of experiments is displayed with only the founder experiment checked. Uncheck it and check the descendant experiment of interest.

If the founder process exits while descendant processes are being followed, collection of data from descendants might continue. The founder experiment directory continues to grow accordingly.