[unix-history] / usr / src / lib / libc / stdio / getc.3

.\"	@(#)getc.3	4.1 (Berkeley) %G%
.\"
.TH GETC 3S 
.AT 3
.SH NAME
getc, getchar, fgetc, getw \- get character or word from stream
.SH SYNOPSIS
.B #include <stdio.h>
.PP
.B int getc(stream)
.br
.SM
.B FILE
.B *stream;
.PP
.B int getchar()
.PP 
.B int fgetc(stream)
.br
.SM
.B FILE
.B *stream;
.PP
.B int getw(stream)
.br
.SM
.B FILE
.B *stream;
.SH DESCRIPTION
.I Getc
returns the next character from the named input
.IR stream .
.PP
.I Getchar()
is identical to 
.IR getc(stdin) .
.PP
.I Fgetc
behaves like 
.I getc,
but is a genuine function, not a macro;
it may be used to save object text.
.PP
.I Getw
returns the next
word (32-bit integer on a VAX-11) from the named input
.IR stream .
It returns the constant
.SM
.B EOF
upon end of file or error, but since that is a good
integer value,
.I feof
and
.IR  ferror (3)
should be used to check the success of
.IR getw .
.I Getw
assumes no special alignment in the file.
.SH "SEE ALSO"
fopen(3), putc(3),
gets(3), scanf(3),
fread(3),
ungetc(3)
.SH DIAGNOSTICS
These functions return the integer constant
.SM
.B EOF
at end of file or upon read error.
.PP
A stop with message,
`Reading bad file', means an attempt has been made to
read from a stream that has not been opened for
reading by
.IR fopen .
.SH BUGS
The end-of-file return from
.I getchar
is incompatible with that in UNIX editions 1-6.
.PP
Because it is implemented as a macro,
.I getc
treats a
.I stream
argument with side effects incorrectly.
In particular,
`getc(*f++);'
doesn't work sensibly.
Commit	Line	Data
e3c5dfdb KM	1	.\" @(#)getc.3 4.1 (Berkeley) %G%
	2	.\"
	3	.TH GETC 3S
	4	.AT 3
	5	.SH NAME
	6	getc, getchar, fgetc, getw \- get character or word from stream
	7	.SH SYNOPSIS
	8	.B #include <stdio.h>
	9	.PP
	10	.B int getc(stream)
	11	.br
	12	.SM
	13	.B FILE
	14	.B *stream;
	15	.PP
	16	.B int getchar()
	17	.PP
	18	.B int fgetc(stream)
	19	.br
	20	.SM
	21	.B FILE
	22	.B *stream;
	23	.PP
	24	.B int getw(stream)
	25	.br
	26	.SM
	27	.B FILE
	28	.B *stream;
	29	.SH DESCRIPTION
	30	.I Getc
	31	returns the next character from the named input
	32	.IR stream .
	33	.PP
	34	.I Getchar()
	35	is identical to
	36	.IR getc(stdin) .
	37	.PP
	38	.I Fgetc
	39	behaves like
	40	.I getc,
	41	but is a genuine function, not a macro;
	42	it may be used to save object text.
	43	.PP
	44	.I Getw
	45	returns the next
	46	word (32-bit integer on a VAX-11) from the named input
	47	.IR stream .
	48	It returns the constant
	49	.SM
	50	.B EOF
	51	upon end of file or error, but since that is a good
	52	integer value,
	53	.I feof
	54	and
	55	.IR ferror (3)
	56	should be used to check the success of
	57	.IR getw .
	58	.I Getw
	59	assumes no special alignment in the file.
	60	.SH "SEE ALSO"
	61	fopen(3), putc(3),
	62	gets(3), scanf(3),
	63	fread(3),
	64	ungetc(3)
65	.SH DIAGNOSTICS
66	These functions return the integer constant
67	.SM
68	.B EOF
69	at end of file or upon read error.
70	.PP
71	A stop with message,
72	`Reading bad file', means an attempt has been made to
73	read from a stream that has not been opened for
74	reading by
75	.IR fopen .
76	.SH BUGS
77	The end-of-file return from
78	.I getchar
79	is incompatible with that in UNIX editions 1-6.
80	.PP
81	Because it is implemented as a macro,
82	.I getc
83	treats a
84	.I stream
85	argument with side effects incorrectly.
86	In particular,
87	`getc(*f++);'
88	doesn't work sensibly.