.TH PSIO 3 "9 November 1987"
.IX psio#(3) "" "\fLpsio\fP(3) \(em \*(Sd buffered input/output package"
.SH NAME
psio \- NeWS buffered input/output package
.SH SYNOPSIS
.B #include \|"psio.h"
.LP
.SM
.B PSFILE
.B *psio_stdin;
.br
.SM
.B PSFILE
.B *psio_stdout;
.br
.SM
.B PSFILE
.B *psio_stderr;
.SH DESCRIPTION
.IX  introduction  "NeWS I/O library functions"  
.IX  "NeWS I/O library functions, introduction to"
.IX  "NeWS buffered I/O library functions, introduction to"
.IX  "library functions"  "introduction to NeWS standard I/O"
The functions described here constitute a user-level I/O buffering
scheme for use when communicating with NeWS. This package is based on
the standard I/O package that comes with Unix. The functions in this
package are used in the same way as the similarly named functions in
Standard I/O.
.LP
The in-line macros
.I psio_getc
and
.IR  psio_putc
handle characters quickly.  The
higher level routines
.IR psio_read ,
.IR psio_printf ,
.IR psio_fprintf ,
.IR psio_write
all use or act as if they use
.I psio_getc
and
.IR psio_putc ;
they can be freely intermixed.
.LP
A file with associated buffering is called a
.IR stream ,
and is declared to be a pointer to a defined type
.SM
.BR PSFILE .
.IR psio_open
creates certain descriptive data for a stream
and returns a pointer to designate the stream in all further transactions.
Normally, there are three open streams with constant pointers declared in
the
.B "psio.h"
include file and associated with the standard open files:
.TP 10n
.B psio_stdin
standard input file
.br
.ns
.TP
.B psio_stdout
standard output file
.br
.ns
.TP
.B psio_stderr
standard error file
.LP
A constant
.SM
.B NULL
(0)
designates a nonexistent pointer.
.LP
An integer constant
.SM
.B EOF
(\-1) is returned upon end-of-file or error by most integer functions that
deal with streams.
.LP
Any module that uses this package
must include the header file of pertinent macro definitions,
as follows:
.PP
.RS
#include \|"psio.h"
.RE
.PP
The functions and constants mentioned in here
are declared in that header file and need no further declaration.
The constants and the following `functions' are
implemented as macros; redeclaration of these names is perilous:
.IR getc ,
.IR putc ,
.IR psio_eof ,
.IR psio_error ,
.IR psio_fileno ,
and
.IR psio_clearerr .
.SH "SEE ALSO"
open(2V), close(2), read(2V), write(2V),
intro(3S),
fclose(3S),
ferror(3S),
fopen(3S),
fread(3S),
getc(3S),
printf(3S),
putc(3S),
ungetc(3S).
.SH DIAGNOSTICS
The value
.SM
.B EOF
is returned uniformly to indicate that a
.SM
.B PSFILE
pointer has not been initialized with
.IR psio_open ,
input (output) has been attempted on an output (input) stream, or a
.SM
.B PSFILE
pointer designates corrupt or otherwise unintelligible
.SM
.B PSFILE
data.
.SH "LIST OF FUNCTIONS"
.sp 2
.nf
.ta \w'psio_clearerr'u+4n
\fIName\fP	\fIDescription\fP
.ta \w'psio_clearerr'u+4n

psio_clearerr	stream status inquiries
psio_close	flush a stream
psio_eof	stream status inquiries
psio_error	stream status inquiries
psio_fdopen	open a stream
psio_flush	close or flush a stream
psio_fileno	stream status inquiries
psio_fprintf	formatted output conversion
psio_getc	get character or integer from stream
psio_open	open a stream
psio_read	buffered binary input/output
psio_printf	formatted output conversion
psio_putc	put character or word on a stream
psio_ungetc	push character back into input stream
psio_write	buffered binary input/output

.fi