How to trace and print out all files that are accessed / used when bash starts?

Question

I'm having a problem and need to print out to the console all files that are being access each time bash is executed on macOS.

Is there a relatively easy method for doing this? Perhaps dtrace might make this fairly straight forward?

Answer 1

If you want to see all the files that any process named 'bash' opens directly, you can do something like this:

$ sudo dtrace -n 'syscall::open*:entry/execname == "bash"/{ trace(copyinstr(arg0)); }'

You may, alternatively, want to see all the files opened between when bash starts and you get to the prompt. For that, you could do something like this:

$ sudo dtrace -n 'syscall::open*:entry/progenyof($target)/{ printf("%s %s", execname, copyinstr(arg0)) }' -c bash

Note that this will show both the file being opened as well as the command accessing it.