HP-UX Reference (11i v3 07/02) - 3 Library Functions N-Z (vol 7)

ManualsBrandsHP ManualsSoftwareHP-UX Reference Manuals

461

462

463

464

465

466

467

468

469

470

stdio(3S) stdio(3S)

NAME

stdio() - standard buffered input/output stream ﬁle package

SYNOPSIS

#include <stdio.h>

DESCRIPTION

The Standard I/O functions described in the subsection (3S) entries of this manual constitute an efﬁcient,

user-level I/O buffering scheme. The getc()

and putc() functions handle characters quickly. The fol-

lowing functions all use or act as if they use

getc() and putc(), and can be freely intermixed:

fgetc() fputs() getchar() putchar()

fgets() fread() gets() puts()

fprintf() fscanf() getw() putw()

fputc() fwrite() printf() scanf()

A ﬁle with associated buffering is called a stream and is declared to be a pointer to a deﬁned type

FILE.

fopen() creates certain descriptive data for a stream and returns a pointer to designate the stream in all

further transactions. Section (3S) library routines operate on this stream.

At program startup, three streams, standard input, standard output, and standard error, are

predeﬁned and do not need to be explicitly opened. When opened, the standard input and standard output

streams are fully buffered if the output refers to a ﬁle and line-buffered if the output refers to a terminal.

The standard error output stream is by default unbuffered. These three streams have the following con-

stant pointers declared in the

<stdio.h> header ﬁle :

stdin standard input ﬁle

stdout standard output ﬁle

stderr standard error ﬁle

A constant, NULL, (0) designates a nonexistent pointer.

An integer-constant,

EOF,(−1) is returned upon end-of-ﬁle or error by most integer functions that deal with

streams (see individual descriptions for details).

An integer constant

BUFSIZ speciﬁes the size of the buffers used by the particular implementation (see

setbuf(3S)).

Any program that uses this package must include the header ﬁle of pertinent macro deﬁnitions as follows:

#include <stdio.h>

The functions and constants mentioned in subsection (3S) entries of this manual are declared in that header

ﬁle and need no further declaration.

A constant _NFILE deﬁnes the default maximum number of open ﬁles allowed per process. To increase

the open ﬁle limit beyond this default value, see getrlimit(2).

WARNINGS

Use of stdio interfaces with a shared read/write ﬁle descriptor on

non-positional devices will

provide undeﬁned behavior. Applications which are doing

stdio operations on non-positional

devices

need to use seperate ﬁle pointers for input and output, even if using the same ﬁle descriptor for

both types of operations.

ERRORS

Invalid stream pointers usually cause grave disorder, possibly including program termination. Individual

function descriptions describe the possible error conditions.