Bi-directional tee. Observing bi-directional stdin/stdout/stderr chatter while invoking a client program and while forwarding as usual like a bi-directional pipe, but also writing all of them into a binary file containing all channels and timestamps that then can be looked at with the bidi-tee-print program. So it behaves like the Unix tee utility, but in both directions.
Useful to debug communication with a subprocess communicating via stdin/stdout.
bidi-tee /tmp/output.log -- other-program parameters to other program
The output (in this example /tmp/output.log) can then be printed using the
bidi-tee-print program, which allows to include timestamps and choose
which channels to print.
Usage: bidi-tee-print [<options>] <bidi-tee-logfile>
-h : this help
-c : toggle print in color (default: on)
-ts : Print timestamp since start of recording.
-ta : Print timestamps as absolute timestamps.
-td : Print delta timestamps relative to last print
-s <select-channel> : comma-separated list of channels to print, e.g. 0,2 prints stdin and stderr
-o <filename> : Output to filename
Timestamps can be printed with the -t option that is qualified with one of three letters:
-ts prints times since the start of the recording, -td prints relative time between outputs and -ta
prints absolute timestamps.
Start Timestamp -ts |
Delta timestamp -td |
|---|---|
 |
 |
The -ta absolute timestamp prints the full timestamp with date and time
Here a practical example from a clangd session, observing what is going on between emacs and clangd talking Language Server Protocol to each other. (red: emacs talking to clangd, blue: clangd answering, green: clangd stderr output).
