xref: /original-bsd/lib/libc/stdio/getc.3 (revision a1c2194a)
1.\" Copyright (c) 1990, 1991 The Regents of the University of California.
2.\" All rights reserved.
3.\"
4.\" This code is derived from software contributed to Berkeley by
5.\" Chris Torek and the American National Standards Committee X3,
6.\" on Information Processing Systems.
7.\"
8.\" %sccs.include.redist.man%
9.\"
10.\"     @(#)getc.3	6.8 (Berkeley) 06/29/91
11.\"
12.Dd
13.Dt GETC 3
14.Os
15.Sh NAME
16.Nm fgetc ,
17.Nm getc ,
18.Nm getchar ,
19.Nm getw
20.Nd get next character or word from input stream
21.Sh SYNOPSIS
22.Fd #include <stdio.h>
23.Ft int
24.Fn fgetc "FILE *stream"
25.Ft int
26.Fn getc "FILE *stream"
27.Ft int
28.Fn getchar
29.Ft int
30.Fn getw "FILE *stream"
31.Sh DESCRIPTION
32The
33.Fn fgetc
34function
35obtains the next input character (if present) from the stream pointed at by
36.Fa stream ,
37or the next character pushed back on the stream via
38.Xr ungetc .
39.Pp
40The
41.Fn getc
42function
43acts essentially identically to
44.Fn fgetc ,
45but is a macro that expands in-line.
46.Pp
47The
48.Fn getchar
49function
50is equivalent to:
51getc with the argument stdin.
52.Pp
53The
54.Fn getw
55function
56obtains the next
57.Em int
58(if present)
59from the stream pointed at by
60.Fa stream .
61.Sh RETURN VALUES
62If successful, these routines return the next requested object
63from the
64.Fa stream .
65If the stream is at end-of-file or a read error occurs,
66the routines return
67.Dv EOF .
68The routines
69.Xr feof 3
70and
71.Xr ferror 3
72must be used to distinguish between end-of-file and error.
73If an error occurs, the global variable
74.Va errno
75is set to indicate the error.
76The end-of-file condition is remembered, even on a terminal, and all
77subsequent attempts to read will return
78.Dv EOF
79until the condition is cleared with
80.Xr clearerr .
81.Sh SEE ALSO
82.Xr ferror 3 ,
83.Xr fread 3 ,
84.Xr fopen 3 ,
85.Xr putc 3 ,
86.Xr ungetc 3
87.Sh STANDARDS
88The
89.Fn fgetc ,
90.Fn getc
91and
92.Fn getchar
93functions
94conform to
95.St -ansiC .
96.Sh BUGS
97Since
98.Dv EOF
99is a valid integer value,
100.Xr feof
101and
102.Xr ferror
103must be used to check for failure after calling
104.Fn getw .
105The size and byte order of an
106.Em int
107varies from one machine to another, and
108.Fn getw
109is not recommended for portable applications.
110.Pp
111