strace

Troubleshooting tool for tracing system calls. More information: https://manned.org/strace.

Start tracing a specific process by its PID:

strace -p {{pid}}
Trace a process and filter output by system call:

strace -p {{pid}} -e {{system_call_name}}
Count time, calls, and errors for each system call and report a summary on program exit:

strace -p {{pid}} -c
Show the time spent in every system call:

strace -p {{pid}} -T
Start tracing a program by executing it:

strace {{program}}
Start tracing file operations of a program:

strace -e trace=file {{program}}