xref: /freebsd/lib/libc/stdio/putc.3 (revision f9218d3d4fd34f082473b3a021c6d4d109fb47cf)
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36.\"     @(#)putc.3	8.1 (Berkeley) 6/4/93
37.\" $FreeBSD$
38.\"
39.Dd January 10, 2003
40.Dt PUTC 3
41.Os
42.Sh NAME
43.Nm fputc ,
44.Nm putc ,
45.Nm putc_unlocked ,
46.Nm putchar ,
47.Nm putchar_unlocked ,
48.Nm putw
49.Nd output a character or word to a stream
50.Sh LIBRARY
51.Lb libc
52.Sh SYNOPSIS
53.In stdio.h
54.Ft int
55.Fn fputc "int c" "FILE *stream"
56.Ft int
57.Fn putc "int c" "FILE *stream"
58.Ft int
59.Fn putc_unlocked "int c" "FILE *stream"
60.Ft int
61.Fn putchar "int c"
62.Ft int
63.Fn putchar_unlocked "int c"
64.Ft int
65.Fn putw "int w" "FILE *stream"
66.Sh DESCRIPTION
67The
68.Fn fputc
69function
70writes the character
71.Fa c
72(converted to an ``unsigned char'')
73to the output stream pointed to by
74.Fa stream .
75.Pp
76The
77.Fn putc
78function acts essentially identically to
79.Fn fputc .
80.Pp
81The
82.Fn putchar
83function
84is identical to
85.Fn putc
86with an output stream of
87.Dv stdout .
88.Pp
89The
90.Fn putw
91function
92writes the specified
93.Vt int
94to the named output
95.Fa stream .
96.Pp
97The
98.Fn putc_unlocked
99and
100.Fn putchar_unlocked
101functions are equivalent to
102.Fn putc
103and
104.Fn putchar
105respectively,
106except that the caller is responsible for locking the stream
107with
108.Xr flockfile 3
109before calling them.
110These functions may be used to avoid the overhead of locking the stream
111for each character, and to avoid output being interspersed from multiple
112threads writing to the same stream.
113.Sh RETURN VALUES
114The functions,
115.Fn fputc ,
116.Fn putc ,
117.Fn putchar ,
118.Fn putc_unlocked
119and
120.Fn putchar_unlocked
121return the character written.
122If an error occurs, the value
123.Dv EOF
124is returned.
125The
126.Fn putw
127function
128returns 0 on success;
129.Dv EOF
130is returned if
131a write error occurs,
132or if an attempt is made to write a read-only stream.
133.Sh SEE ALSO
134.Xr ferror 3 ,
135.Xr flockfile 3 ,
136.Xr fopen 3 ,
137.Xr getc 3 ,
138.Xr putwc 3 ,
139.Xr stdio 3
140.Sh STANDARDS
141The functions
142.Fn fputc ,
143.Fn putc ,
144and
145.Fn putchar ,
146conform to
147.St -isoC .
148The
149.Fn putc_unlocked
150and
151.Fn putchar_unlocked
152functions conform to
153.St -p1003.1-2001 .
154A function
155.Fn putw
156function appeared in
157.At v6 .
158.Sh BUGS
159The size and byte order of an
160.Vt int
161varies from one machine to another, and
162.Fn putw
163is not recommended for portable applications.
164