fgets.c revision f582340a6a48588aa50da17e1620e8f91b146941
11dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* $OpenBSD: fgets.c,v 1.10 2005/08/08 08:05:36 espie Exp $ */ 21dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/*- 31dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Copyright (c) 1990, 1993 41dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * The Regents of the University of California. All rights reserved. 51dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 61dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * This code is derived from software contributed to Berkeley by 71dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Chris Torek. 81dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 91dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Redistribution and use in source and binary forms, with or without 101dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * modification, are permitted provided that the following conditions 111dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * are met: 121dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 1. Redistributions of source code must retain the above copyright 131dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * notice, this list of conditions and the following disclaimer. 141dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 2. Redistributions in binary form must reproduce the above copyright 151dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * notice, this list of conditions and the following disclaimer in the 161dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * documentation and/or other materials provided with the distribution. 171dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 3. Neither the name of the University nor the names of its contributors 181dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * may be used to endorse or promote products derived from this software 191dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * without specific prior written permission. 201dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 211dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * SUCH DAMAGE. 321dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 331dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 341dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <stdio.h> 351dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <string.h> 361dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include "local.h" 371dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 381dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* 391dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Read at most n-1 characters from the given file. 401dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Stop when a newline has been read, or the count runs out. 411dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Return first argument, or NULL if no characters were read. 421dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Do not return NULL if n == 1. 431dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 441dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectchar * 451dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectfgets(char *buf, int n, FILE *fp) 461dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project{ 471dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project size_t len; 481dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project char *s; 491dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project unsigned char *p, *t; 501dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 511dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (n <= 0) /* sanity check */ 521dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (NULL); 531dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 54f582340a6a48588aa50da17e1620e8f91b146941Kenny Root FLOCKFILE(fp); 551dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project _SET_ORIENTATION(fp, -1); 561dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project s = buf; 571dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project n--; /* leave space for NUL */ 581dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project while (n != 0) { 591dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* 601dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * If the buffer is empty, refill it. 611dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 621dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (fp->_r <= 0) { 631dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (__srefill(fp)) { 641dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* EOF/error: stop with partial or no line */ 65f582340a6a48588aa50da17e1620e8f91b146941Kenny Root if (s == buf) { 66f582340a6a48588aa50da17e1620e8f91b146941Kenny Root FUNLOCKFILE(fp); 671dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (NULL); 68f582340a6a48588aa50da17e1620e8f91b146941Kenny Root } 69a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa break; 70a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa } 711dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 721dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project len = fp->_r; 731dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project p = fp->_p; 74a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa 751dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* 761dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Scan through at most n bytes of the current buffer, 771dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * looking for '\n'. If found, copy up to and including 781dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * newline, and stop. Otherwise, copy entire chunk 791dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * and loop. 801dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 811dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if ((int)len > n) 821dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project len = n; 831dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project t = memchr((void *)p, '\n', len); 841dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (t != NULL) { 851dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project len = ++t - p; 861dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_r -= len; 871dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_p = t; 881dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project (void)memcpy((void *)s, (void *)p, len); 891dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project s[len] = '\0'; 90f582340a6a48588aa50da17e1620e8f91b146941Kenny Root FUNLOCKFILE(fp); 911dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (buf); 921dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 931dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_r -= len; 941dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_p += len; 951dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project (void)memcpy((void *)s, (void *)p, len); 961dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project s += len; 971dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project n -= len; 981dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 991dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project *s = '\0'; 100f582340a6a48588aa50da17e1620e8f91b146941Kenny Root FUNLOCKFILE(fp); 1011dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (buf); 1021dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project} 103