Stdio provides streams for standard input, standard output, and
standard error. These streams correspond to file handles returned
GetStandardFileHandles procedure in the
INTERFACEThe initialization of these streams depends on the underlying operating system.
Stdio; IMPORT Rd, Wr; VAR stdin: Rd.T; stdout: Wr.T; stderr: Wr.T; bufferedStderr: Wr.T; END Stdio.
If the standard error stream is directed to a terminal, it will be
unbuffered, so that explicit
Wr.Flush calls are unnecessary for
interactive programs. A buffered version of the standard error
stream is also provided, but programs should not use both
If the streams are directed to or from random-access files, they will be seekable.
It is possible that
stderr is equal to
programs that perform seek operations on
stdout should take care
not to destroy output data when writing error messages.