xref: /freebsd/lib/libc/stdio/getc.3 (revision 522ccf3f353a439b7938a4f10adfab7d912210a2)
158f0484fSRodney W. Grimes.\" Copyright (c) 1990, 1991, 1993
258f0484fSRodney W. Grimes.\"	The Regents of the University of California.  All rights reserved.
358f0484fSRodney W. Grimes.\"
458f0484fSRodney W. Grimes.\" This code is derived from software contributed to Berkeley by
558f0484fSRodney W. Grimes.\" Chris Torek and the American National Standards Committee X3,
658f0484fSRodney W. Grimes.\" on Information Processing Systems.
758f0484fSRodney W. Grimes.\"
858f0484fSRodney W. Grimes.\" Redistribution and use in source and binary forms, with or without
958f0484fSRodney W. Grimes.\" modification, are permitted provided that the following conditions
1058f0484fSRodney W. Grimes.\" are met:
1158f0484fSRodney W. Grimes.\" 1. Redistributions of source code must retain the above copyright
1258f0484fSRodney W. Grimes.\"    notice, this list of conditions and the following disclaimer.
1358f0484fSRodney W. Grimes.\" 2. Redistributions in binary form must reproduce the above copyright
1458f0484fSRodney W. Grimes.\"    notice, this list of conditions and the following disclaimer in the
1558f0484fSRodney W. Grimes.\"    documentation and/or other materials provided with the distribution.
1658f0484fSRodney W. Grimes.\" 3. All advertising materials mentioning features or use of this software
1758f0484fSRodney W. Grimes.\"    must display the following acknowledgement:
1858f0484fSRodney W. Grimes.\"	This product includes software developed by the University of
1958f0484fSRodney W. Grimes.\"	California, Berkeley and its contributors.
2058f0484fSRodney W. Grimes.\" 4. Neither the name of the University nor the names of its contributors
2158f0484fSRodney W. Grimes.\"    may be used to endorse or promote products derived from this software
2258f0484fSRodney W. Grimes.\"    without specific prior written permission.
2358f0484fSRodney W. Grimes.\"
2458f0484fSRodney W. Grimes.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
2558f0484fSRodney W. Grimes.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
2658f0484fSRodney W. Grimes.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
2758f0484fSRodney W. Grimes.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
2858f0484fSRodney W. Grimes.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
2958f0484fSRodney W. Grimes.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
3058f0484fSRodney W. Grimes.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
3158f0484fSRodney W. Grimes.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
3258f0484fSRodney W. Grimes.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
3358f0484fSRodney W. Grimes.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
3458f0484fSRodney W. Grimes.\" SUCH DAMAGE.
3558f0484fSRodney W. Grimes.\"
3658f0484fSRodney W. Grimes.\"     @(#)getc.3	8.1 (Berkeley) 6/4/93
377f3dea24SPeter Wemm.\" $FreeBSD$
3858f0484fSRodney W. Grimes.\"
39cbee408dSTim J. Robbins.Dd January 10, 2003
4058f0484fSRodney W. Grimes.Dt GETC 3
4158f0484fSRodney W. Grimes.Os
4258f0484fSRodney W. Grimes.Sh NAME
4358f0484fSRodney W. Grimes.Nm fgetc ,
4458f0484fSRodney W. Grimes.Nm getc ,
45522ccf3fSRuslan Ermilov.Nm getc_unlocked ,
4658f0484fSRodney W. Grimes.Nm getchar ,
47522ccf3fSRuslan Ermilov.Nm getchar_unlocked ,
4858f0484fSRodney W. Grimes.Nm getw
4958f0484fSRodney W. Grimes.Nd get next character or word from input stream
5025bb73e0SAlexey Zelkin.Sh LIBRARY
5125bb73e0SAlexey Zelkin.Lb libc
5258f0484fSRodney W. Grimes.Sh SYNOPSIS
5332eef9aeSRuslan Ermilov.In stdio.h
5458f0484fSRodney W. Grimes.Ft int
5558f0484fSRodney W. Grimes.Fn fgetc "FILE *stream"
5658f0484fSRodney W. Grimes.Ft int
5758f0484fSRodney W. Grimes.Fn getc "FILE *stream"
5858f0484fSRodney W. Grimes.Ft int
59cbee408dSTim J. Robbins.Fn getc_unlocked "FILE *stream"
60cbee408dSTim J. Robbins.Ft int
6158f0484fSRodney W. Grimes.Fn getchar
6258f0484fSRodney W. Grimes.Ft int
63cbee408dSTim J. Robbins.Fn getchar_unlocked "FILE *stream"
64cbee408dSTim J. Robbins.Ft int
6558f0484fSRodney W. Grimes.Fn getw "FILE *stream"
6658f0484fSRodney W. Grimes.Sh DESCRIPTION
6758f0484fSRodney W. GrimesThe
6858f0484fSRodney W. Grimes.Fn fgetc
6958f0484fSRodney W. Grimesfunction
7058f0484fSRodney W. Grimesobtains the next input character (if present) from the stream pointed at by
7158f0484fSRodney W. Grimes.Fa stream ,
7258f0484fSRodney W. Grimesor the next character pushed back on the stream via
73926bb1cfSBruce Evans.Xr ungetc 3 .
7458f0484fSRodney W. Grimes.Pp
7558f0484fSRodney W. GrimesThe
7658f0484fSRodney W. Grimes.Fn getc
7758f0484fSRodney W. Grimesfunction
7858f0484fSRodney W. Grimesacts essentially identically to
7990310300STim J. Robbins.Fn fgetc .
8058f0484fSRodney W. Grimes.Pp
8158f0484fSRodney W. GrimesThe
8258f0484fSRodney W. Grimes.Fn getchar
8358f0484fSRodney W. Grimesfunction
847f55e48eSDima Dorfmanis equivalent to
857bc66825SDima Dorfman.Fn getc stdin .
8658f0484fSRodney W. Grimes.Pp
8758f0484fSRodney W. GrimesThe
8858f0484fSRodney W. Grimes.Fn getw
8958f0484fSRodney W. Grimesfunction
9058f0484fSRodney W. Grimesobtains the next
9116fb6849SRuslan Ermilov.Vt int
9258f0484fSRodney W. Grimes(if present)
9358f0484fSRodney W. Grimesfrom the stream pointed at by
9458f0484fSRodney W. Grimes.Fa stream .
95cbee408dSTim J. Robbins.Pp
96cbee408dSTim J. RobbinsThe
97cbee408dSTim J. Robbins.Fn getc_unlocked
98cbee408dSTim J. Robbinsand
99cbee408dSTim J. Robbins.Fn getchar_unlocked
100cbee408dSTim J. Robbinsfunctions are equivalent to
101cbee408dSTim J. Robbins.Fn getc
102cbee408dSTim J. Robbinsand
103cbee408dSTim J. Robbins.Fn getchar
104cbee408dSTim J. Robbinsrespectively,
105cbee408dSTim J. Robbinsexcept that the caller is responsible for locking the stream
106cbee408dSTim J. Robbinswith
107522ccf3fSRuslan Ermilov.Xr flockfile 3
108cbee408dSTim J. Robbinsbefore calling them.
109cbee408dSTim J. RobbinsThese functions may be used to avoid the overhead of locking the stream
110cbee408dSTim J. Robbinsfor each character, and to avoid input being dispersed among multiple
111cbee408dSTim J. Robbinsthreads reading from the same stream.
11258f0484fSRodney W. Grimes.Sh RETURN VALUES
11358f0484fSRodney W. GrimesIf successful, these routines return the next requested object
11458f0484fSRodney W. Grimesfrom the
11558f0484fSRodney W. Grimes.Fa stream .
116cfad593dSTony FinchCharacter values are returned as an
11716fb6849SRuslan Ermilov.Vt "unsigned char"
118cfad593dSTony Finchconverted to an
11916fb6849SRuslan Ermilov.Vt int .
12058f0484fSRodney W. GrimesIf the stream is at end-of-file or a read error occurs,
12158f0484fSRodney W. Grimesthe routines return
12258f0484fSRodney W. Grimes.Dv EOF .
12358f0484fSRodney W. GrimesThe routines
12458f0484fSRodney W. Grimes.Xr feof 3
12558f0484fSRodney W. Grimesand
12658f0484fSRodney W. Grimes.Xr ferror 3
12758f0484fSRodney W. Grimesmust be used to distinguish between end-of-file and error.
12858f0484fSRodney W. GrimesIf an error occurs, the global variable
12958f0484fSRodney W. Grimes.Va errno
13058f0484fSRodney W. Grimesis set to indicate the error.
13158f0484fSRodney W. GrimesThe end-of-file condition is remembered, even on a terminal, and all
13258f0484fSRodney W. Grimessubsequent attempts to read will return
13358f0484fSRodney W. Grimes.Dv EOF
13458f0484fSRodney W. Grimesuntil the condition is cleared with
135926bb1cfSBruce Evans.Xr clearerr 3 .
13658f0484fSRodney W. Grimes.Sh SEE ALSO
13758f0484fSRodney W. Grimes.Xr ferror 3 ,
138cbee408dSTim J. Robbins.Xr flockfile 3 ,
13958f0484fSRodney W. Grimes.Xr fopen 3 ,
14075141cc9SWolfram Schneider.Xr fread 3 ,
141ce04c110STim J. Robbins.Xr getwc 3 ,
14258f0484fSRodney W. Grimes.Xr putc 3 ,
14358f0484fSRodney W. Grimes.Xr ungetc 3
14458f0484fSRodney W. Grimes.Sh STANDARDS
14558f0484fSRodney W. GrimesThe
14658f0484fSRodney W. Grimes.Fn fgetc ,
14758f0484fSRodney W. Grimes.Fn getc
14858f0484fSRodney W. Grimesand
14958f0484fSRodney W. Grimes.Fn getchar
15058f0484fSRodney W. Grimesfunctions
15158f0484fSRodney W. Grimesconform to
152588a200cSRuslan Ermilov.St -isoC .
153cbee408dSTim J. RobbinsThe
154cbee408dSTim J. Robbins.Fn getc_unlocked
155cbee408dSTim J. Robbinsand
156cbee408dSTim J. Robbins.Fn getchar_unlocked
157cbee408dSTim J. Robbinsfunctions conform to
158cbee408dSTim J. Robbins.St -p1003.1-2001 .
15958f0484fSRodney W. Grimes.Sh BUGS
16058f0484fSRodney W. GrimesSince
16158f0484fSRodney W. Grimes.Dv EOF
16258f0484fSRodney W. Grimesis a valid integer value,
163926bb1cfSBruce Evans.Xr feof 3
16458f0484fSRodney W. Grimesand
165926bb1cfSBruce Evans.Xr ferror 3
16658f0484fSRodney W. Grimesmust be used to check for failure after calling
16758f0484fSRodney W. Grimes.Fn getw .
16858f0484fSRodney W. GrimesThe size and byte order of an
16916fb6849SRuslan Ermilov.Vt int
17058f0484fSRodney W. Grimesvaries from one machine to another, and
17158f0484fSRodney W. Grimes.Fn getw
17258f0484fSRodney W. Grimesis not recommended for portable applications.
17358f0484fSRodney W. Grimes.Pp
174