xref: /netbsd-src/lib/libc/stdio/getc.3 (revision 481fca6e59249d8ffcf24fef7cfbe7b131bfb080)
1.\"	$NetBSD: getc.3,v 1.5 1998/04/28 20:58:01 fair Exp $
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3.\" Copyright (c) 1990, 1991, 1993
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6.\" This code is derived from software contributed to Berkeley by
7.\" Chris Torek and the American National Standards Committee X3,
8.\" on Information Processing Systems.
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38.\"     @(#)getc.3	8.1 (Berkeley) 6/4/93
39.\"
40.Dd June 4, 1993
41.Dt GETC 3
42.Os
43.Sh NAME
44.Nm fgetc ,
45.Nm getc ,
46.Nm getchar ,
47.Nm getw
48.Nd get next character or word from input stream
49.Sh LIBRARY
50.Lb libc
51.Sh SYNOPSIS
52.Fd #include <stdio.h>
53.Ft int
54.Fn fgetc "FILE *stream"
55.Ft int
56.Fn getc "FILE *stream"
57.Ft int
58.Fn getchar
59.Ft int
60.Fn getw "FILE *stream"
61.Sh DESCRIPTION
62The
63.Fn fgetc
64function
65obtains the next input character (if present) from the stream pointed at by
66.Fa stream ,
67or the next character pushed back on the stream via
68.Xr ungetc 3 .
69.Pp
70The
71.Fn getc
72function
73acts essentially identically to
74.Fn fgetc ,
75but is a macro that expands in-line.
76.Pp
77The
78.Fn getchar
79function
80is equivalent to:
81getc with the argument stdin.
82.Pp
83The
84.Fn getw
85function
86obtains the next
87.Em int
88(if present)
89from the stream pointed at by
90.Fa stream .
91.Sh RETURN VALUES
92If successful, these routines return the next requested object
93from the
94.Fa stream .
95If the stream is at end-of-file or a read error occurs,
96the routines return
97.Dv EOF .
98The routines
99.Xr feof 3
100and
101.Xr ferror 3
102must be used to distinguish between end-of-file and error.
103If an error occurs, the global variable
104.Va errno
105is set to indicate the error.
106The end-of-file condition is remembered, even on a terminal, and all
107subsequent attempts to read will return
108.Dv EOF
109until the condition is cleared with
110.Xr clearerr 3 .
111.Sh SEE ALSO
112.Xr ferror 3 ,
113.Xr fread 3 ,
114.Xr fopen 3 ,
115.Xr putc 3 ,
116.Xr ungetc 3
117.Sh STANDARDS
118The
119.Fn fgetc ,
120.Fn getc
121and
122.Fn getchar
123functions
124conform to
125.St -ansiC .
126.Sh BUGS
127Since
128.Dv EOF
129is a valid integer value,
130.Xr feof 3
131and
132.Xr ferror 3
133must be used to check for failure after calling
134.Fn getw .
135The size and byte order of an
136.Em int
137varies from one machine to another, and
138.Fn getw
139is not recommended for portable applications.
140.Pp
141