NAME
fgetc, getc,
getc_unlocked, getchar,
getchar_unlocked, getw
— get next character or word
from input stream
LIBRARY
library “libc”
SYNOPSIS
#include
<stdio.h>
int
fgetc(FILE
*stream);
int
getc(FILE
*stream);
int
getc_unlocked(FILE
*stream);
int
getchar(void);
int
getchar_unlocked(void);
int
getw(FILE
*stream);
DESCRIPTION
Thefgetc()
function obtains the next input character (if present) from the stream pointed
at by stream, or the next character pushed back on the
stream via ungetc(3).
The
getc()
function acts essentially identically to fgetc(),
but is a macro that expands in-line.
The
getchar()
function is equivalent to
getc(stdin).
The
getw()
function obtains the next int (if present) from the
stream pointed at by stream.
The
getc_unlocked()
and
getchar_unlocked()
functions are equivalent to getc() and
getchar() respectively, except that the caller is
responsible for locking the stream with
flockfile(3) before calling them. These functions may be used
to avoid the overhead of locking the stream for each character, and to avoid
input being dispersed among multiple threads reading from the same
stream.
RETURN VALUES
If successful, these routines return the next requested object
from the stream. Character values are returned as an
unsigned char converted to an
int. If the stream is at end-of-file or a read error
occurs, the routines return EOF. The routines
feof(3) and
ferror(3) must be used to distinguish between end-of-file and error.
If an error occurs, the global variable 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
EOF until the condition is cleared with
clearerr(3).
SEE ALSO
ferror(3), flockfile(3), fopen(3), fread(3), getwc(3), putc(3), ungetc(3)
STANDARDS
The fgetc(),
getc() and getchar()
functions conform to ISO/IEC 9899:1990
(“ISO C90”). The
getc_unlocked() and
getchar_unlocked() functions conform to
IEEE Std 1003.1-2001 (“POSIX.1”).
BUGS
Since EOF is a valid integer value,
feof(3) and
ferror(3) must be used to check for failure after calling
getw(). The size and byte order of an
int varies from one machine to another, and
getw() is not recommended for portable
applications.