1123256Sscottl/*- 2123256Sscottl * Copyright (c) 1990, 1993 3123256Sscottl * The Regents of the University of California. All rights reserved. 4123256Sscottl * 5123256Sscottl * This code is derived from software contributed to Berkeley by 6123256Sscottl * Chris Torek. 7123256Sscottl * 8123256Sscottl * Redistribution and use in source and binary forms, with or without 9123256Sscottl * modification, are permitted provided that the following conditions 10123256Sscottl * are met: 11123256Sscottl * 1. Redistributions of source code must retain the above copyright 12123256Sscottl * notice, this list of conditions and the following disclaimer. 13123256Sscottl * 2. Redistributions in binary form must reproduce the above copyright 14123256Sscottl * notice, this list of conditions and the following disclaimer in the 15123256Sscottl * documentation and/or other materials provided with the distribution. 16123256Sscottl * 3. Neither the name of the University nor the names of its contributors 17123256Sscottl * may be used to endorse or promote products derived from this software 18123256Sscottl * without specific prior written permission. 19123256Sscottl * 20123256Sscottl * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21123256Sscottl * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22123256Sscottl * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23123256Sscottl * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24123256Sscottl * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25123256Sscottl * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26123256Sscottl * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27123256Sscottl * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28123256Sscottl * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29123256Sscottl * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30123256Sscottl * SUCH DAMAGE. 31123256Sscottl */ 32206622Suqs 33123256Sscottl#if defined(LIBC_SCCS) && !defined(lint) 34123256Sscottlstatic char sccsid[] = "@(#)fgetln.c 8.2 (Berkeley) 1/2/94"; 35123256Sscottl#endif /* LIBC_SCCS and not lint */ 36131736Sru#include <sys/cdefs.h> 37123256Sscottl__FBSDID("$FreeBSD: releng/10.3/lib/libc/stdio/fgetln.c 249808 2013-04-23 13:33:13Z emaste $"); 38123256Sscottl 39123256Sscottl#include "namespace.h" 40123256Sscottl#include <stdio.h> 41123256Sscottl#include <stdlib.h> 42131736Sru#include <string.h> 43131736Sru#include "un-namespace.h" 44131736Sru#include "libc_private.h" 45131736Sru#include "local.h" 46131736Sru 47131736Sru/* 48128951Shmp * Expand the line buffer. Return -1 on error. 49123492Sroam#ifdef notdef 50131736Sru * The `new size' does not account for a terminating '\0', 51131736Sru * so we add 1 here. 52131736Sru#endif 53131736Sru */ 54123256Sscottlint 55128951Shmp__slbexpand(FILE *fp, size_t newsize) 56131736Sru{ 57131736Sru void *p; 58131736Sru 59123256Sscottl#ifdef notdef 60131736Sru ++newsize; 61123256Sscottl#endif 62131736Sru if (fp->_lb._size >= newsize) 63131736Sru return (0); 64131736Sru if ((p = realloc(fp->_lb._base, newsize)) == NULL) 65128951Shmp return (-1); 66131736Sru fp->_lb._base = p; 67131736Sru fp->_lb._size = newsize; 68131736Sru return (0); 69123256Sscottl} 70131736Sru 71131736Sru/* 72131736Sru * Get an input line. The returned pointer often (but not always) 73128951Shmp * points into a stdio buffer. Fgetln does not alter the text of 74128951Shmp * the returned line (which is thus not a C string because it will 75131736Sru * not necessarily end with '\0'), but does allow callers to modify 76131736Sru * it if they wish. Thus, we set __SMOD in case the caller does. 77131736Sru */ 78131736Sruchar * 79131736Srufgetln(FILE *fp, size_t *lenp) 80131736Sru{ 81131736Sru unsigned char *p; 82131736Sru size_t len; 83131736Sru size_t off; 84131736Sru 85131736Sru FLOCKFILE(fp); 86131736Sru ORIENT(fp, -1); 87131736Sru /* make sure there is input */ 88123256Sscottl if (fp->_r <= 0 && __srefill(fp)) { 89123256Sscottl *lenp = 0; 90123256Sscottl FUNLOCKFILE(fp); 91123256Sscottl return (NULL); 92123256Sscottl } 93147647Shmp 94123256Sscottl /* look for a newline in the input */ 95 if ((p = memchr((void *)fp->_p, '\n', (size_t)fp->_r)) != NULL) { 96 char *ret; 97 98 /* 99 * Found one. Flag buffer as modified to keep fseek from 100 * `optimising' a backward seek, in case the user stomps on 101 * the text. 102 */ 103 p++; /* advance over it */ 104 ret = (char *)fp->_p; 105 *lenp = len = p - fp->_p; 106 fp->_flags |= __SMOD; 107 fp->_r -= len; 108 fp->_p = p; 109 FUNLOCKFILE(fp); 110 return (ret); 111 } 112 113 /* 114 * We have to copy the current buffered data to the line buffer. 115 * As a bonus, though, we can leave off the __SMOD. 116 * 117 * OPTIMISTIC is length that we (optimistically) expect will 118 * accommodate the `rest' of the string, on each trip through the 119 * loop below. 120 */ 121#define OPTIMISTIC 80 122 123 for (len = fp->_r, off = 0;; len += fp->_r) { 124 size_t diff; 125 126 /* 127 * Make sure there is room for more bytes. Copy data from 128 * file buffer to line buffer, refill file and look for 129 * newline. The loop stops only when we find a newline. 130 */ 131 if (__slbexpand(fp, len + OPTIMISTIC)) 132 goto error; 133 (void)memcpy((void *)(fp->_lb._base + off), (void *)fp->_p, 134 len - off); 135 off = len; 136 if (__srefill(fp)) 137 break; /* EOF or error: return partial line */ 138 if ((p = memchr((void *)fp->_p, '\n', (size_t)fp->_r)) == NULL) 139 continue; 140 141 /* got it: finish up the line (like code above) */ 142 p++; 143 diff = p - fp->_p; 144 len += diff; 145 if (__slbexpand(fp, len)) 146 goto error; 147 (void)memcpy((void *)(fp->_lb._base + off), (void *)fp->_p, 148 diff); 149 fp->_r -= diff; 150 fp->_p = p; 151 break; 152 } 153 *lenp = len; 154#ifdef notdef 155 fp->_lb._base[len] = 0; 156#endif 157 FUNLOCKFILE(fp); 158 return ((char *)fp->_lb._base); 159 160error: 161 *lenp = 0; /* ??? */ 162 FUNLOCKFILE(fp); 163 return (NULL); /* ??? */ 164} 165