# truss > Troubleshooting tool for tracing system calls. > SunOS equivalent of strace. > More information: . - Start tracing a program by executing it, following all child processes: `truss -f {{program}}` - Start tracing a specific process by its PID: `truss -p {{pid}}` - Start tracing a program by executing it, showing arguments and environment variables: `truss -a -e {{program}}` - Count time, calls, and errors for each system call and report a summary on program exit: `truss -c -p {{pid}}` - Trace a process filtering output by system call: `truss -p {{pid}} -t {{system_call_name}}`