A Writable Stream that represents the child process's stdin.

If a child process waits to read all of its input, the child will not continue until this stream has been closed via end().

If the child was spawned with stdio[0] set to anything other than 'pipe', then this will be null.

subprocess.stdin is an alias for subprocess.stdio[0]. Both properties will refer to the same value.

The subprocess.stdin property can be null or undefined if the child process could not be successfully spawned.