TH FGETC 2
SH NAME
fgetc, getc, getchar, fputc, putc, putchar, ungetc, fgets, gets, fputs, puts, fread, fwrite \- Stdio input and output
SH SYNOPSIS
B #include <stdio.h>
ta \w'\fLlong 'u
PP
B
int fgetc(FILE *f)
PP
B
int getc(FILE *f)
PP
B
int getchar(void)
PP
B
int fputc(int c, FILE *f)
PP
B
int putc(int c, FILE *f)
PP
B
int putchar(int c)
PP
B
int ungetc(int c, FILE *f)
PP
B
char *fgets(char *s, int n, FILE *f)
PP
B
char *gets(char *s)
PP
B
int fputs(char *s, FILE *f)
PP
B
int puts(char *s)
PP
B
long fread(void *ptr, long itemsize, long nitems, FILE *stream)
PP
B
long fwrite(void *ptr, long itemsize, long nitems, FILE *stream)
SH DESCRIPTION
The functions described here work on open Stdio streams (see
IR fopen ).
PP
I Fgetc
returns as an
B int
the next
B unsigned
B char
from input stream
IR f .
If the stream is at end-of-file, the end-of-file indicator for the
stream is set and
I fgetc
returns
BR EOF .
If a read error occurs, the error indicator for the stream is set and
I fgetc
returns
BR EOF .
I Getc
is like
I fgetc
except that it is implemented as a macro.
I Getchar
is like
I getc
except that it always reads from
BR stdin .
PP
I Ungetc
pushes character
I c
back onto the input stream
BR f .
The pushed-back character will be returned by subsequent reads in
the reverse order of their pushing.
A successful intervening
IR fseek ,
IR fsetpos ,
or
I rewind
on
I f
discards any pushed-back characters for
IR f .
One character of push-back is guaranteed.
I Ungetc
returns the character pushed back (converted to
B unsigned
BR char ),
or
B EOF
if the operation fails.
A successful call to
I ungetc
clears the end-of-file indicator for the stream.
The file position indicator for the stream after reading or discarding
all pushed-back characters is the same as it was before the
characters were pushed back.
PP
I Fputc
writes character
I c
(converted to
B unsigned
BR char )
to output stream
IR f
at the position indicated by the position indicator for the stream
and advances the indicator appropriately.
If the file cannot support positioning requests, or if the stream was
opened with append mode, the character is appended to the output stream.
I Fputc
returns the character written or
B EOF
if there was a write error.
I Putc
is like
IR fputc
but is implemented as a macro.
I Putchar
is like
I putc
except that it always writes to
BR stdout .
PP
All other input takes place as if characters were read by successive
calls to
I fgetc
and all other output takes place as if characters were written by
successive calls to
IR fputc .
PP
I Fgets
reads up to and including the next newline, but not past end-of-file
or more than
IR n -1
characters, from stream
I f
into array
IR s .
A null character is written immediately after the last character read
into the array (if any characters are read at all).
I Fgets
returns
I s
if successful, otherwise a null pointer.
I Gets
is similar to
IR fgets
except that it always reads from
B stdin
and it discards the terminating newline, if any.
I Gets
does not check for overflow of the receiving array, so its use is deprecated.
PP
I Fputs
writes the string
I s
to stream
IR f ,
returning
B EOF
if a write error occurred, otherwise a nonnegative value.
The terminating null character is not written.
I Puts
is the same, writing to
BR stdout .
PP
I Fread
reads from the named input
IR stream
at most
I nitems
of data of size
I itemsize
and the type of
I *ptr
into a block beginning at
IR ptr .
It returns the number of items actually read.
PP
I Fwrite
appends to the named output
I stream
at most
I nitems
of data of size
I itemsize
and the type of
I *ptr
from a block beginning at
IR ptr .
It returns the number of items actually written.
SH SOURCE
B /sys/src/libstdio
SH "SEE ALSO"
IR read (2),
IR fopen (2),
IR bio (2)
SH BUGS
Stdio does not handle
SM UTF
or runes; use Bio instead.
