streamsstdin
streamsstdin refers to the standard input data stream for a running program. On POSIX systems it is represented by file descriptor 0 and, in higher-level languages, by convenient abstractions named stdin in various APIs. Conceptually, streamsstdin is the default source of input from the user or environment, delivered to the process as data arrives.
Across programming languages, streamsstdin is exposed through language-specific abstractions. In C, the stream is the FILE*
Input to streamsstdin can come from the keyboard in interactive mode or be redirected from files and
Behavior and performance vary with buffering and encoding. Many environments apply buffering to streamsstdin, affecting latency