1.\" $OpenBSD: getc.3,v 1.17 2023/09/28 01:51:00 jsg Exp $ 2.\" 3.\" Copyright (c) 1990, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 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. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.Dd $Mdocdate: September 28 2023 $ 35.Dt GETC 3 36.Os 37.Sh NAME 38.Nm fgetc , 39.Nm getc , 40.Nm getchar , 41.Nm getw 42.Nd get next character or word from input stream 43.Sh SYNOPSIS 44.In stdio.h 45.Ft int 46.Fn fgetc "FILE *stream" 47.Ft int 48.Fn getc "FILE *stream" 49.Ft int 50.Fn getchar "void" 51.Ft int 52.Fn getw "FILE *stream" 53.Sh DESCRIPTION 54The 55.Fn fgetc 56function obtains the next input character (if present) from the stream 57pointed at by 58.Fa stream , 59or the next character pushed back on the stream via 60.Xr ungetc 3 . 61.Pp 62The 63.Fn getc 64function acts essentially identically to 65.Fn fgetc , 66but is a macro that expands in-line. 67.Pp 68The 69.Fn getchar 70function is equivalent to 71.Fn getc 72with the argument 73.Em stdin . 74.Pp 75The 76.Fn getw 77function obtains the next 78.Vt int 79(if present) 80from the stream pointed at by 81.Fa stream . 82.Sh RETURN VALUES 83If successful, these routines return the next requested object from the 84.Fa stream . 85If the stream is at end-of-file or a read error occurs, the routines return 86.Dv EOF . 87The routines 88.Xr feof 3 89and 90.Xr ferror 3 91must be used to distinguish between end-of-file and error. 92If an error occurs, the global variable 93.Va errno 94is set to indicate the error. 95The end-of-file condition is remembered, even on a terminal, and all 96subsequent attempts to read will return 97.Dv EOF 98until the condition is cleared with 99.Xr clearerr 3 . 100.Sh SEE ALSO 101.Xr ferror 3 , 102.Xr fopen 3 , 103.Xr fread 3 , 104.Xr getwc 3 , 105.Xr putc 3 , 106.Xr ungetc 3 107.Sh STANDARDS 108The 109.Fn fgetc , 110.Fn getc , 111and 112.Fn getchar 113functions conform to 114.St -ansiC . 115.Sh HISTORY 116The 117.Fn getc 118and 119.Fn getw 120functions first appeared in 121.At v1 ; 122.Fn getchar 123in 124.At v2 ; 125and 126.Fn fgetc 127in 128.At v7 . 129.Sh BUGS 130Since 131.Dv EOF 132is a valid integer value, 133.Xr feof 3 134and 135.Xr ferror 3 136must be used to check for failure after calling 137.Fn getw . 138.Pp 139Since the size and byte order of an 140.Vt int 141may vary from one machine to another, 142.Fn getw 143is not recommended for portable applications. 144