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.\" 34.Dd April 4, 2020 35.Dt GETC 3 36.Os 37.Sh NAME 38.Nm fgetc , 39.Nm getc , 40.Nm getc_unlocked , 41.Nm getchar , 42.Nm getchar_unlocked , 43.Nm getw 44.Nd get next character or word from input stream 45.Sh LIBRARY 46.Lb libc 47.Sh SYNOPSIS 48.In stdio.h 49.Ft int 50.Fn fgetc "FILE *stream" 51.Ft int 52.Fn getc "FILE *stream" 53.Ft int 54.Fn getc_unlocked "FILE *stream" 55.Ft int 56.Fn getchar void 57.Ft int 58.Fn getchar_unlocked void 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 81.Fn getc stdin . 82.Pp 83The 84.Fn getw 85function 86obtains the next 87.Vt int 88(if present) 89from the stream pointed at by 90.Fa stream . 91.Pp 92The 93.Fn getc_unlocked 94and 95.Fn getchar_unlocked 96functions are equivalent to 97.Fn getc 98and 99.Fn getchar 100respectively, 101except that the caller is responsible for locking the stream 102with 103.Xr flockfile 3 104before calling them. 105These functions may be used to avoid the overhead of locking the stream 106for each character, and to avoid input being dispersed among multiple 107threads reading from the same stream. 108.Sh RETURN VALUES 109If successful, these routines return the next requested object 110from the 111.Fa stream . 112Character values are returned as an 113.Vt "unsigned char" 114converted to an 115.Vt int . 116If the stream is at end-of-file or a read error occurs, 117the routines return 118.Dv EOF . 119The routines 120.Xr feof 3 121and 122.Xr ferror 3 123must be used to distinguish between end-of-file and error. 124If an error occurs, the global variable 125.Va errno 126is set to indicate the error. 127The end-of-file condition is remembered, even on a terminal, and all 128subsequent attempts to read will return 129.Dv EOF 130until the condition is cleared with 131.Xr clearerr 3 . 132.Sh SEE ALSO 133.Xr ferror 3 , 134.Xr flockfile 3 , 135.Xr fopen 3 , 136.Xr fread 3 , 137.Xr getwc 3 , 138.Xr putc 3 , 139.Xr ungetc 3 140.Sh STANDARDS 141The 142.Fn fgetc , 143.Fn getc , 144and 145.Fn getchar 146functions 147conform to 148.St -isoC . 149The 150.Fn getc_unlocked 151and 152.Fn getchar_unlocked 153functions conform to 154.St -p1003.1-2001 . 155.Sh HISTORY 156The 157.Fn getc 158and 159.Fn getw 160functions appeared in a similar form in 161.At v1 ; 162and were integrated into stdio in 163.At v7 ; 164.Fn getchar 165in 166.At v4 ; 167and 168.Fn fgetc 169in 170.At v7 . 171.Sh BUGS 172Since 173.Dv EOF 174is a valid integer value, 175.Xr feof 3 176and 177.Xr ferror 3 178must be used to check for failure after calling 179.Fn getw . 180The size and byte order of an 181.Vt int 182varies from one machine to another, and 183.Fn getw 184is not recommended for portable applications. 185