The processes are specified directly using PIDs or as program names (with either the -a / --all or -p / --program options). In the all case, the set of all running processes is searched for a basename (1) match on name . In the program case, process identifiers are extracted from files in the $PCP_RUN_DIR directrory where file names are matched on name .pid.
The -n / --dry-run option reports the list of process identifiers that would have been signalled, but no signals are actually sent.
If a signal is not specified, then the TERM signal will be sent. The list of supported signals is reported when using the -l / --list option.
On Linux and UNIX platforms, pmsignal is a simple wrapper around the kill (1) command. On Windows, the is no direct equivalent to this mechanism, and so an alternate mechanism has been implemented - this is only honoured by PCP tools, however, not all Windows utilities.