ministrace

ministrace is a small strace implementation by Nelson Elhage (@nelhage).

ministrace is a minimal implementation of strace originally about 70 lines of C. It isn't nearly as functional as the real thing, but you can use it to learn most of what you need to know about the core interfaces it uses.

ministrace was written for a blog post, which explains in some detail how it works.

Usage

ministrace [-n <system call name>|-s <system call int>] <program> <program args>

Basic ministrace usage just takes a command line:

ministrace <program> <program args>

This will run the program provided with the given arguments, and print out a sequence of all the system calls which made by the program.

You can also specify a specific system call, using -n sys_call_name or -s sys_call_number:

ministrace -n <system call name> <program> <program args>
ministrace -s <system call int> <program> <program args>

This will print out a sequence of system calls which are made, and block (waiting for an enter on ministrace's terminal) whenever the program is about to execute the specified system call.

Additional features

ministrace is deliberately minimal, demonstrating only the bare minimum of features necessary to understand approximately how a program like strace works. If you're interested in seeing a worked-out version with a few more of the details, @therealthingy has created a fork based on this code base with many additional features.