.\" Copyright (c) 1980 Regents of the University of California.
.\" All rights reserved. The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
.\" @(#)stdio.3s 6.2 (Berkeley) 5/13/86
.TH STDIO 3S "May 13, 1986"
stdio \- standard buffered input/output package
The functions described in section 3S constitute a user-level buffering
scheme. The in-line macros
handle characters quickly. The higher level routines
they can be freely intermixed.
A file with associated buffering is called a
and is declared to be a pointer to a defined type
creates certain descriptive data for a stream
and returns a pointer to designate the stream in all further transactions.
There are three normally open streams with constant pointers declared in
the include file and associated with the standard open files:
designates no stream at all.
(\-1) is returned upon end of file or error by integer functions that
Any routine that uses the standard input/output package
must include the header file
of pertinent macro definitions.
The functions and constants mentioned in sections labeled 3S
are declared in the include file and need no further declaration.
The constants, and the following `functions' are
implemented as macros; redeclaration of these names is perilous:
open(2), close(2), read(2), write(2), fread(3S), fseek(3S), f*(3S)
is returned uniformly to indicate that a
pointer has not been initialized with
input (output) has been attempted on an output (input) stream, or a
pointer designates corrupt or otherwise unintelligible
For purposes of efficiency, this implementation of the standard library
has been changed to line buffer output to a terminal by default and attempts
to do this transparently by flushing the output whenever a
from the standard input is necessary. This is almost always transparent,
but may cause confusion or malfunctioning of programs which use
standard i/o routines but use
themselves to read from the standard input.
In cases where a large amount of computation is done after printing
part of a line on an output terminal, it is necessary to
the standard output before going off and computing so that the output
The standard buffered functions do not interact well with certain other
library and system functions, especially \fIvfork\fP and \fIabort\fP.
.ta \w'setlinebuf'u+2n +\w'setbuf.3s'u+10n
\fIName\fP \fIAppears on Page\fP \fIDescription\fP
.ta \w'setlinebuf'u+4n +\w'setbuf.3s'u+4n
clearerr ferror.3s stream status inquiries
fclose fclose.3s close or flush a stream
fdopen fopen.3s open a stream
feof ferror.3s stream status inquiries
ferror ferror.3s stream status inquiries
fflush fclose.3s close or flush a stream
fgetc getc.3s get character or word from stream
fgets gets.3s get a string from a stream
fileno ferror.3s stream status inquiries
fopen fopen.3s open a stream
fprintf printf.3s formatted output conversion
fputc putc.3s put character or word on a stream
fputs puts.3s put a string on a stream
fread fread.3s buffered binary input/output
freopen fopen.3s open a stream
fscanf scanf.3s formatted input conversion
fseek fseek.3s reposition a stream
ftell fseek.3s reposition a stream
fwrite fread.3s buffered binary input/output
getc getc.3s get character or word from stream
getchar getc.3s get character or word from stream
gets gets.3s get a string from a stream
getw getc.3s get character or word from stream
printf printf.3s formatted output conversion
putc putc.3s put character or word on a stream
putchar putc.3s put character or word on a stream
puts puts.3s put a string on a stream
putw putc.3s put character or word on a stream
rewind fseek.3s reposition a stream
scanf scanf.3s formatted input conversion
setbuf setbuf.3s assign buffering to a stream
setbuffer setbuf.3s assign buffering to a stream
setlinebuf setbuf.3s assign buffering to a stream
sprintf printf.3s formatted output conversion
sscanf scanf.3s formatted input conversion
ungetc ungetc.3s push character back into input stream
projects / unix-history / blob