10133944b09d1c0a35041f7a41eb6bfb660144f4fElliott Hughes/* $OpenBSD: fgets.c,v 1.14 2009/11/09 00:18:27 kurt 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. 17b2e1abda0503874a5bb097e0b55ad4f8ce211a8dElliott Hughes * 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 340133944b09d1c0a35041f7a41eb6bfb660144f4fElliott Hughes#include <errno.h> 351dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <stdio.h> 361dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <string.h> 371dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include "local.h" 381dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 391dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* 401dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Read at most n-1 characters from the given file. 411dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Stop when a newline has been read, or the count runs out. 421dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Return first argument, or NULL if no characters were read. 430133944b09d1c0a35041f7a41eb6bfb660144f4fElliott Hughes * Do not return NULL if n == 1. 441dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 451dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectchar * 460133944b09d1c0a35041f7a41eb6bfb660144f4fElliott Hughesfgets(char *buf, int n, FILE *fp) 471dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project{ 481dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project size_t len; 491dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project char *s; 501dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project unsigned char *p, *t; 511dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 520133944b09d1c0a35041f7a41eb6bfb660144f4fElliott Hughes if (n <= 0) { /* sanity check */ 530133944b09d1c0a35041f7a41eb6bfb660144f4fElliott Hughes errno = EINVAL; 541dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (NULL); 550133944b09d1c0a35041f7a41eb6bfb660144f4fElliott Hughes } 561dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 57f582340a6a48588aa50da17e1620e8f91b146941Kenny Root FLOCKFILE(fp); 580133944b09d1c0a35041f7a41eb6bfb660144f4fElliott Hughes _SET_ORIENTATION(fp, -1); 591dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project s = buf; 601dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project n--; /* leave space for NUL */ 611dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project while (n != 0) { 621dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* 631dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * If the buffer is empty, refill it. 641dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 650133944b09d1c0a35041f7a41eb6bfb660144f4fElliott Hughes if (fp->_r <= 0) { 661dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (__srefill(fp)) { 671dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* EOF/error: stop with partial or no line */ 68f582340a6a48588aa50da17e1620e8f91b146941Kenny Root if (s == buf) { 69f582340a6a48588aa50da17e1620e8f91b146941Kenny Root FUNLOCKFILE(fp); 701dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (NULL); 716b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes } 72a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa break; 73a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa } 741dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 750133944b09d1c0a35041f7a41eb6bfb660144f4fElliott Hughes len = fp->_r; 761dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project p = fp->_p; 77a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa 781dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* 791dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Scan through at most n bytes of the current buffer, 801dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * looking for '\n'. If found, copy up to and including 811dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * newline, and stop. Otherwise, copy entire chunk 821dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * and loop. 831dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 846b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes if (len > n) 851dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project len = n; 861dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project t = memchr((void *)p, '\n', len); 871dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (t != NULL) { 881dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project len = ++t - p; 891dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_r -= len; 901dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_p = t; 911dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project (void)memcpy((void *)s, (void *)p, len); 920133944b09d1c0a35041f7a41eb6bfb660144f4fElliott Hughes s[len] = '\0'; 93f582340a6a48588aa50da17e1620e8f91b146941Kenny Root FUNLOCKFILE(fp); 941dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (buf); 951dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 961dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_r -= len; 971dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_p += len; 981dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project (void)memcpy((void *)s, (void *)p, len); 991dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project s += len; 1001dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project n -= len; 1011dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1020133944b09d1c0a35041f7a41eb6bfb660144f4fElliott Hughes *s = '\0'; 103f582340a6a48588aa50da17e1620e8f91b146941Kenny Root FUNLOCKFILE(fp); 1041dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (buf); 1051dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project} 106