QProcess lacks interface to supply standard input data from a memory buffer

Standard output and standard error can be read using the signals readyReadStandardOutput/readyReadStandardError and readAllStandardOutput()/readAllStandardError() functions.

But standard input can only be read from a file or from the standard input of a calling process, and not from a memory buffer.

Fundamentally, no file is required for communicating to an external process.