Question

I am porting some existing C code to run on Android. This C code writes lots of output to stdout/stderr. I need to capture this output, either in a memory buffer or a file, so I can then send it by email or otherwise share it.

How can I achieve this, ideally without modifying the existing C code?

Note: this question is NOT about redirecting the output to adb or logcat; I need to buffer the output locally on the device. I am aware of the following questions, which do not appear to address my query:

• Why is redirecting stdout/stderr on android not working?
• Android NDK Native LIB, What to do about existing stdio?

Answer 1

stdout is path 1 and stderr is path 2. Knowing this, you can establish new path(s) that you want to be the output destination, then coerce them into stdout and/or stderr. There’s an example showing how to do this at practical examples use dup or dup2.