fgets.c revision 6b05c8e28017518fae04a3a601d0d245916561d2
11dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/*- 21dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Copyright (c) 1990, 1993 31dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * The Regents of the University of California. All rights reserved. 41dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 51dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * This code is derived from software contributed to Berkeley by 61dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Chris Torek. 71dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 81dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Redistribution and use in source and binary forms, with or without 91dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * modification, are permitted provided that the following conditions 101dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * are met: 111dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 1. Redistributions of source code must retain the above copyright 121dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * notice, this list of conditions and the following disclaimer. 131dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 2. Redistributions in binary form must reproduce the above copyright 141dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * notice, this list of conditions and the following disclaimer in the 151dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * documentation and/or other materials provided with the distribution. 166b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes * 4. Neither the name of the University nor the names of its contributors 171dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * may be used to endorse or promote products derived from this software 181dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * without specific prior written permission. 191dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 201dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 211dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 221dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 231dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 241dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 251dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 261dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 271dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 281dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 291dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 301dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * SUCH DAMAGE. 311dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 321dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 336b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes#if defined(LIBC_SCCS) && !defined(lint) 346b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughesstatic char sccsid[] = "@(#)fgets.c 8.2 (Berkeley) 12/22/93"; 356b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes#endif /* LIBC_SCCS and not lint */ 366b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes#include <sys/cdefs.h> 376b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes__FBSDID("$FreeBSD$"); 386b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes 396b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes#include "namespace.h" 401dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <stdio.h> 411dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <string.h> 426b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes#include "un-namespace.h" 431dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include "local.h" 446b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes#include "libc_private.h" 451dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 461dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* 471dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Read at most n-1 characters from the given file. 481dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Stop when a newline has been read, or the count runs out. 491dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Return first argument, or NULL if no characters were read. 501dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 511dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectchar * 526b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughesfgets(buf, n, fp) 536b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes char *buf; 546b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes int n; 556b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes FILE *fp; 561dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project{ 571dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project size_t len; 581dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project char *s; 591dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project unsigned char *p, *t; 601dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 611dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (n <= 0) /* sanity check */ 621dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (NULL); 631dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 64f582340a6a48588aa50da17e1620e8f91b146941Kenny Root FLOCKFILE(fp); 656b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes ORIENT(fp, -1); 661dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project s = buf; 671dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project n--; /* leave space for NUL */ 681dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project while (n != 0) { 691dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* 701dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * If the buffer is empty, refill it. 711dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 726b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes if ((len = fp->_r) <= 0) { 731dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (__srefill(fp)) { 741dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* EOF/error: stop with partial or no line */ 75f582340a6a48588aa50da17e1620e8f91b146941Kenny Root if (s == buf) { 76f582340a6a48588aa50da17e1620e8f91b146941Kenny Root FUNLOCKFILE(fp); 771dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (NULL); 786b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes } 79a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa break; 80a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa } 816b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes len = fp->_r; 821dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 831dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project p = fp->_p; 84a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa 851dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* 861dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Scan through at most n bytes of the current buffer, 871dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * looking for '\n'. If found, copy up to and including 881dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * newline, and stop. Otherwise, copy entire chunk 891dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * and loop. 901dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 916b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes if (len > n) 921dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project len = n; 931dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project t = memchr((void *)p, '\n', len); 941dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (t != NULL) { 951dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project len = ++t - p; 961dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_r -= len; 971dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_p = t; 981dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project (void)memcpy((void *)s, (void *)p, len); 996b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes s[len] = 0; 100f582340a6a48588aa50da17e1620e8f91b146941Kenny Root FUNLOCKFILE(fp); 1011dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (buf); 1021dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1031dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_r -= len; 1041dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_p += len; 1051dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project (void)memcpy((void *)s, (void *)p, len); 1061dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project s += len; 1071dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project n -= len; 1081dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1096b05c8e28017518fae04a3a601d0d245916561d2Elliott Hughes *s = 0; 110f582340a6a48588aa50da17e1620e8f91b146941Kenny Root FUNLOCKFILE(fp); 1111dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (buf); 1121dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project} 113