source: rtems-libbsd/freebsd/lib/libc/stdio/fgetln.c @ f41a394

55-freebsd-126-freebsd-12freebsd-9.3
Last change on this file since f41a394 was 0a57e1d, checked in by Sebastian Huber <sebastian.huber@…>, on Nov 6, 2013 at 8:35:05 AM

Reduce divergence from FreeBSD sources

  • Property mode set to 100644
File size: 4.7 KB
Line 
1#include <machine/rtems-bsd-user-space.h>
2
3/*-
4 * Copyright (c) 1990, 1993
5 *      The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Chris Torek.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#if defined(LIBC_SCCS) && !defined(lint)
36static char sccsid[] = "@(#)fgetln.c    8.2 (Berkeley) 1/2/94";
37#endif /* LIBC_SCCS and not lint */
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD$");
40
41#include "namespace.h"
42#include <stdio.h>
43#include <stdlib.h>
44#include <string.h>
45#include "un-namespace.h"
46#include "libc_private.h"
47#include "local.h"
48
49/*
50 * Expand the line buffer.  Return -1 on error.
51#ifdef notdef
52 * The `new size' does not account for a terminating '\0',
53 * so we add 1 here.
54#endif
55 */
56int
57__slbexpand(FILE *fp, size_t newsize)
58{
59        void *p;
60
61#ifdef notdef
62        ++newsize;
63#endif
64        if (fp->_lb._size >= newsize)
65                return (0);
66        if ((p = realloc(fp->_lb._base, newsize)) == NULL)
67                return (-1);
68        fp->_lb._base = p;
69        fp->_lb._size = newsize;
70        return (0);
71}
72
73/*
74 * Get an input line.  The returned pointer often (but not always)
75 * points into a stdio buffer.  Fgetln does not alter the text of
76 * the returned line (which is thus not a C string because it will
77 * not necessarily end with '\0'), but does allow callers to modify
78 * it if they wish.  Thus, we set __SMOD in case the caller does.
79 */
80char *
81fgetln(FILE *fp, size_t *lenp)
82{
83        unsigned char *p;
84        size_t len;
85        size_t off;
86
87        FLOCKFILE(fp);
88        ORIENT(fp, -1);
89        /* make sure there is input */
90        if (fp->_r <= 0 && __srefill(fp)) {
91                *lenp = 0;
92                FUNLOCKFILE(fp);
93                return (NULL);
94        }
95
96        /* look for a newline in the input */
97        if ((p = memchr((void *)fp->_p, '\n', (size_t)fp->_r)) != NULL) {
98                char *ret;
99
100                /*
101                 * Found one.  Flag buffer as modified to keep fseek from
102                 * `optimising' a backward seek, in case the user stomps on
103                 * the text.
104                 */
105                p++;            /* advance over it */
106                ret = (char *)fp->_p;
107                *lenp = len = p - fp->_p;
108#ifndef __rtems__
109                fp->_flags |= __SMOD;
110#endif /* __rtems__ */
111                fp->_r -= len;
112                fp->_p = p;
113                FUNLOCKFILE(fp);
114                return (ret);
115        }
116
117        /*
118         * We have to copy the current buffered data to the line buffer.
119         * As a bonus, though, we can leave off the __SMOD.
120         *
121         * OPTIMISTIC is length that we (optimistically) expect will
122         * accomodate the `rest' of the string, on each trip through the
123         * loop below.
124         */
125#define OPTIMISTIC 80
126
127        for (len = fp->_r, off = 0;; len += fp->_r) {
128                size_t diff;
129
130                /*
131                 * Make sure there is room for more bytes.  Copy data from
132                 * file buffer to line buffer, refill file and look for
133                 * newline.  The loop stops only when we find a newline.
134                 */
135                if (__slbexpand(fp, len + OPTIMISTIC))
136                        goto error;
137                (void)memcpy((void *)(fp->_lb._base + off), (void *)fp->_p,
138                    len - off);
139                off = len;
140                if (__srefill(fp))
141                        break;  /* EOF or error: return partial line */
142                if ((p = memchr((void *)fp->_p, '\n', (size_t)fp->_r)) == NULL)
143                        continue;
144
145                /* got it: finish up the line (like code above) */
146                p++;
147                diff = p - fp->_p;
148                len += diff;
149                if (__slbexpand(fp, len))
150                        goto error;
151                (void)memcpy((void *)(fp->_lb._base + off), (void *)fp->_p,
152                    diff);
153                fp->_r -= diff;
154                fp->_p = p;
155                break;
156        }
157        *lenp = len;
158#ifdef notdef
159        fp->_lb._base[len] = 0;
160#endif
161        FUNLOCKFILE(fp);
162        return ((char *)fp->_lb._base);
163
164error:
165        *lenp = 0;              /* ??? */
166        FUNLOCKFILE(fp);
167        return (NULL);          /* ??? */
168}
Note: See TracBrowser for help on using the repository browser.