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The input and output functions, types and macros defined in
<stdio.h>
represent nearly one third of the
library.
A stream is a source or destination of data that may
be associated with a disk or other peripheral. The library
supports text streams and binary streams, although on some systems,
notably UNIX, these are identical. A text stream is a sequence
of lines; each line has zero or more characters and is terminated by
'\n'
. An environment may need to convert a text
stream to or from some other representation (such as mapping
'\n'
to carriage return and linefeed). A binary
stream is a sequence of unprocessed bytes that record internal data,
with the property that if it written, then read back on the same
system, it will compare equal.
A stream is connected to a file or device by opening
it; the connection is broken by closing the stream.
Opening a file returns a pointer to an object of type
FILE
, which records whatever information is necessary to
control the stream. We will use "file pointer" and "stream"
interchangeably when there is no ambiguity.
When a program begins execution, the three streams stdin
,
stdout
, and stderr
are already open.
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Last modified: Fri Feb 25 13:50:56 2000