1.\" $NetBSD: getc.3,v 1.8 2002/02/07 07:00:25 ross 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. All advertising materials mentioning features or use of this software 19.\" must display the following acknowledgement: 20.\" This product includes software developed by the University of 21.\" California, Berkeley and its contributors. 22.\" 4. Neither the name of the University nor the names of its contributors 23.\" may be used to endorse or promote products derived from this software 24.\" without specific prior written permission. 25.\" 26.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36.\" SUCH DAMAGE. 37.\" 38.\" @(#)getc.3 8.1 (Berkeley) 6/4/93 39.\" 40.Dd April 25, 2001 41.Dt GETC 3 42.Os 43.Sh NAME 44.Nm fgetc , 45.Nm getc , 46.Nm getchar , 47.Nm getc_unlocked , 48.Nm getchar_unlocked , 49.Nm getw 50.Nd get next character or word from input stream 51.Sh LIBRARY 52.Lb libc 53.Sh SYNOPSIS 54.Fd #include \*[Lt]stdio.h\*[Gt] 55.Ft int 56.Fn fgetc "FILE *stream" 57.Ft int 58.Fn getc "FILE *stream" 59.Ft int 60.Fn getchar 61.Ft int 62.Fn getc_unlocked "FILE *stream" 63.Ft int 64.Fn getchar_unlocked 65.Ft int 66.Fn getw "FILE *stream" 67.Sh DESCRIPTION 68The 69.Fn fgetc 70function 71obtains the next input character (if present) from the stream pointed at by 72.Fa stream , 73or the next character pushed back on the stream via 74.Xr ungetc 3 . 75.Pp 76The 77.Fn getc 78function 79acts essentially identically to 80.Fn fgetc , 81but is a macro that expands in-line. 82.Pp 83The 84.Fn getchar 85function 86is equivalent to: 87getc with the argument stdin. 88.Pp 89The 90.Fn getc_unlocked 91and 92.Fn getchar_unlocked 93functions provide functionality identical to that of 94.Fn getc 95and 96.Fn getchar , 97respectively, but do not perform implicit locking of the streams they 98operate on. 99In multi-threaded programs they may be used 100.Em only 101within a scope in which the stream 102has been successfully locked by the calling thread using either 103.Xr flockfile 3 104or 105.Xr ftrylockfile 3 , 106and may later be released using 107.Xr funlockfile 3 . 108.Pp 109The 110.Fn getw 111function 112obtains the next 113.Em int 114(if present) 115from the stream pointed at by 116.Fa stream . 117.Sh RETURN VALUES 118If successful, these routines return the next requested object 119from the 120.Fa stream . 121If the stream is at end-of-file or a read error occurs, 122the routines return 123.Dv EOF . 124The routines 125.Xr feof 3 126and 127.Xr ferror 3 128must be used to distinguish between end-of-file and error. 129If an error occurs, the global variable 130.Va errno 131is set to indicate the error. 132The end-of-file condition is remembered, even on a terminal, and all 133subsequent attempts to read will return 134.Dv EOF 135until the condition is cleared with 136.Xr clearerr 3 . 137.Sh SEE ALSO 138.Xr ferror 3 , 139.Xr fopen 3 , 140.Xr fread 3 , 141.Xr putc 3 , 142.Xr ungetc 3 143.Sh STANDARDS 144The 145.Fn fgetc , 146.Fn getc 147and 148.Fn getchar 149functions 150conform to 151.St -ansiC . 152The 153.Fn getc_unlocked 154and 155.Fn getchar_unlocked 156functions conform to 157.St -p1003.1-96 . 158.Sh BUGS 159Since 160.Dv EOF 161is a valid integer value, 162.Xr feof 3 163and 164.Xr ferror 3 165must be used to check for failure after calling 166.Fn getw . 167The size and byte order of an 168.Em int 169varies from one machine to another, and 170.Fn getw 171is not recommended for portable applications. 172