strace is a useful diagnostic, instructional, and debugging tool. It can save lots of headache. System administrators, diagnosticians and trouble-shooters will find it invaluable for solving problems with programs for which the source is not readily available since they do not need to be recompiled in order to trace them. This is also useful to submit bug reports to open source developers.

via Debugging Tip: Trace the Process and See What It is Doing with strace.

Run strace against /bin/foo and capture its output to a text file in output.txt:
$ strace -o output.txt /bin/foo