# strace > Troubleshooting tool for tracing system calls. > More information: . - Start tracing a specific process by its PID: `strace {{[-p|--attach]}} {{pid}}` - Trace a process and filter output by system call [e]xpression: `strace {{[-p|--attach]}} {{pid}} -e {{system_call,system_call2,...}}` - Count time, calls, and errors for each system call and report a summary on program exit: `strace {{[-p|--attach]}} {{pid}} {{[-c|--summary-only]}}` - Show the time spent in every system call and specify the maximum string size to print: `strace {{[-p|--attach]}} {{pid}} {{[-T|--syscall-times]}} {{[-s|--string-limit]}} {{32}}` - Start tracing a program by executing it: `strace {{program}}` - Start tracing file operations of a program: `strace -e trace=file {{program}}` - Start tracing network operations of a program as well as all its forked and child processes, saving the output to a file: `strace {{[-f|--follow-forks]}} -e trace=network {{[-o|--output]}} {{trace.txt}} {{program}}`