1.\" Copyright (c) 1990, 1991, 1993 2.\" The Regents of the University of California. 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.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)getc.3 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD$ 34.\" 35.Dd April 4, 2020 36.Dt GETC 3 37.Os 38.Sh NAME 39.Nm fgetc , 40.Nm getc , 41.Nm getc_unlocked , 42.Nm getchar , 43.Nm getchar_unlocked , 44.Nm getw 45.Nd get next character or word from input stream 46.Sh LIBRARY 47.Lb libc 48.Sh SYNOPSIS 49.In stdio.h 50.Ft int 51.Fn fgetc "FILE *stream" 52.Ft int 53.Fn getc "FILE *stream" 54.Ft int 55.Fn getc_unlocked "FILE *stream" 56.Ft int 57.Fn getchar void 58.Ft int 59.Fn getchar_unlocked void 60.Ft int 61.Fn getw "FILE *stream" 62.Sh DESCRIPTION 63The 64.Fn fgetc 65function 66obtains the next input character (if present) from the stream pointed at by 67.Fa stream , 68or the next character pushed back on the stream via 69.Xr ungetc 3 . 70.Pp 71The 72.Fn getc 73function 74acts essentially identically to 75.Fn fgetc , 76but is a macro that expands in-line. 77.Pp 78The 79.Fn getchar 80function 81is equivalent to 82.Fn getc stdin . 83.Pp 84The 85.Fn getw 86function 87obtains the next 88.Vt int 89(if present) 90from the stream pointed at by 91.Fa stream . 92.Pp 93The 94.Fn getc_unlocked 95and 96.Fn getchar_unlocked 97functions are equivalent to 98.Fn getc 99and 100.Fn getchar 101respectively, 102except that the caller is responsible for locking the stream 103with 104.Xr flockfile 3 105before calling them. 106These functions may be used to avoid the overhead of locking the stream 107for each character, and to avoid input being dispersed among multiple 108threads reading from the same stream. 109.Sh RETURN VALUES 110If successful, these routines return the next requested object 111from the 112.Fa stream . 113Character values are returned as an 114.Vt "unsigned char" 115converted to an 116.Vt int . 117If the stream is at end-of-file or a read error occurs, 118the routines return 119.Dv EOF . 120The routines 121.Xr feof 3 122and 123.Xr ferror 3 124must be used to distinguish between end-of-file and error. 125If an error occurs, the global variable 126.Va errno 127is set to indicate the error. 128The end-of-file condition is remembered, even on a terminal, and all 129subsequent attempts to read will return 130.Dv EOF 131until the condition is cleared with 132.Xr clearerr 3 . 133.Sh SEE ALSO 134.Xr ferror 3 , 135.Xr flockfile 3 , 136.Xr fopen 3 , 137.Xr fread 3 , 138.Xr getwc 3 , 139.Xr putc 3 , 140.Xr ungetc 3 141.Sh STANDARDS 142The 143.Fn fgetc , 144.Fn getc , 145and 146.Fn getchar 147functions 148conform to 149.St -isoC . 150The 151.Fn getc_unlocked 152and 153.Fn getchar_unlocked 154functions conform to 155.St -p1003.1-2001 . 156.Sh HISTORY 157The 158.Fn getc 159and 160.Fn getw 161functions appeared in a similar form in 162.At v1 ; 163and were integrated into stdio in 164.At v7 ; 165.Fn getchar 166in 167.At v4 ; 168and 169.Fn fgetc 170in 171.At v7 . 172.Sh BUGS 173Since 174.Dv EOF 175is a valid integer value, 176.Xr feof 3 177and 178.Xr ferror 3 179must be used to check for failure after calling 180.Fn getw . 181The size and byte order of an 182.Vt int 183varies from one machine to another, and 184.Fn getw 185is not recommended for portable applications. 186