Snoop new process execution. Uses DTrace.
Syntax execsnoop [-a|-A|-ejhsvZ] [-c command] Key -a print all data -A dump all data, space delimited -e safe output, parseable. This prevents the ARGS field containing "\n"s, to assist postprocessing. -j print project ID -s print start time, us -v print start time, string -Z print zonename -c command command name to snoop
execsnoop prints details of new processes as they are executed. Details such as UID, PID and argument listing are printed out. This program is very useful to examine short lived processes that would not normally appear in a prstat or "ps -ef" listing. Sometimes applications will run hundreds of short lived processes in their normal startup cycle, a behaviour that is easily monitored with execsnoop.
Since this uses DTrace, only users with root privileges can run this command.
execsnoop will run forever until Ctrl-C is hit.
Default output, print processes as they are executed,
Print human readable timestamps,
$ execsnoop -v
$ execsnoop -Z
Snoop this command only,
$ execsnoop -c ls
UID User ID PID Process ID PPID Parent Process ID COMM command name for the process ARGS argument listing for the process ZONE zonename PROJ project ID TIME timestamp for the exec event, us STRTIME timestamp for the exec event, string
"It's the way to educate your eyes. Stare. Pry, listen eavesdrop. Die knowing something. You are not here long" ~ Walker Evans
Related macOS commands:
iosnoop - Snoop I/O events as they occur
dtrace - generic front-end to the DTrace facility
Top 10 DTrace scripts - Brandan Gregg (author of the dtrace book)