usr/src/lib/libc/stdio/getc.3

.\" Copyright (c) 1990, 1991 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Chris Torek and the American National Standards Committee X3,
.\" on Information Processing Systems.
.\"
.\" %sccs.include.redist.man%
.\"
.\"     @(#)getc.3      6.8 (Berkeley) %G%
.\"
.Dd
.Dt GETC 3
.Os
.Sh NAME
.Nm fgetc ,
.Nm getc ,
.Nm getchar ,
.Nm getw
.Nd get next character or word from input stream
.Sh SYNOPSIS
.Fd #include <stdio.h>
.Ft int
.Fn fgetc "FILE *stream"
.Ft int
.Fn getc "FILE *stream"
.Ft int
.Fn getchar
.Ft int
.Fn getw "FILE *stream"
.Sh DESCRIPTION
The
.Fn fgetc
function
obtains the next input character (if present) from the stream pointed at by
.Fa stream ,
or the next character pushed back on the stream via
.Xr ungetc .
.Pp
The
.Fn getc
function
acts essentially identically to
.Fn fgetc ,
but is a macro that expands in-line.
.Pp
The
.Fn getchar
function
is equivalent to:
getc with the argument stdin.
.Pp
The
.Fn getw
function
obtains the next
.Em int
(if present)
from the stream pointed at by
.Fa stream .
.Sh RETURN VALUES
If successful, these routines return the next requested object
from the
.Fa stream .
If the stream is at end-of-file or a read error occurs,
the routines return
.Dv EOF .
The routines
.Xr feof 3
and
.Xr ferror 3
must be used to distinguish between end-of-file and error.
If an error occurs, the global variable
.Va errno
is set to indicate the error.
The end-of-file condition is remembered, even on a terminal, and all
subsequent attempts to read will return
.Dv EOF
until the condition is cleared with
.Xr clearerr .
.Sh SEE ALSO
.Xr ferror 3 ,
.Xr fread 3 ,
.Xr fopen 3 ,
.Xr putc 3 ,
.Xr ungetc 3
.Sh STANDARDS
The
.Fn fgetc ,
.Fn getc
and
.Fn getchar
functions
conform to
.St -ansiC .
.Sh BUGS
Since
.Dv EOF
is a valid integer value,
.Xr feof
and
.Xr ferror
must be used to check for failure after calling
.Fn getw .
The size and byte order of an
.Em int
varies from one machine to another, and
.Fn getw
is not recommended for portable applications.
.Pp