gets.c revision 331722
1/*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Chris Torek. 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 33#if defined(LIBC_SCCS) && !defined(lint) 34static char sccsid[] = "@(#)gets.c 8.1 (Berkeley) 6/4/93"; 35#endif /* LIBC_SCCS and not lint */ 36#include <sys/cdefs.h> 37__FBSDID("$FreeBSD: stable/11/lib/libc/stdio/gets.c 331722 2018-03-29 02:50:57Z eadler $"); 38 39#include "namespace.h" 40#include <unistd.h> 41#include <stdio.h> 42#include "un-namespace.h" 43#include "libc_private.h" 44#include "local.h" 45 46__warn_references(gets, "warning: this program uses gets(), which is unsafe."); 47 48char * 49gets(char *buf) 50{ 51 int c; 52 char *s, *ret; 53 static int warned; 54 static const char w[] = 55 "warning: this program uses gets(), which is unsafe.\n"; 56 57 FLOCKFILE_CANCELSAFE(stdin); 58 ORIENT(stdin, -1); 59 if (!warned) { 60 (void) _write(STDERR_FILENO, w, sizeof(w) - 1); 61 warned = 1; 62 } 63 for (s = buf; (c = __sgetc(stdin)) != '\n'; ) { 64 if (c == EOF) 65 if (s == buf) { 66 ret = NULL; 67 goto end; 68 } else 69 break; 70 else 71 *s++ = c; 72 } 73 *s = 0; 74 ret = buf; 75end: 76 FUNLOCKFILE_CANCELSAFE(); 77 return (ret); 78} 79