C ++获取函数读取的字节数

Question

Is there a way to get number of bytes read by the function ?

Using function **getrusage** I can get the count of

 ru_inblock;       /* block input operations */

But how to get number of bytes read by function ?

Answer 1

You can't. You will need to preload your own SO that overrides read(2) which calls it and counts how many bytes are actually read.

Answer 2

Use strace(1) or a debugger. You will have to postprocess the output a bit, but all the information about the data transferred by syscalls is there.