Subversion Repositories shark

Rev

Details | Last modification | View Log | RSS feed

Rev Author Line No. Line
2 pj 1
/*-
2
 * Copyright (c) 1990, 1993
3
 *      The Regents of the University of California.  All rights reserved.
4
 *
5
 * This code is derived from software contributed to Berkeley by
6
 * Chris Torek.
7
 *
8
 * Redistribution and use in source and binary forms, with or without
9
 * modification, are permitted provided that the following conditions
10
 * are met:
11
 * 1. Redistributions of source code must retain the above copyright
12
 *    notice, this list of conditions and the following disclaimer.
13
 * 2. Redistributions in binary form must reproduce the above copyright
14
 *    notice, this list of conditions and the following disclaimer in the
15
 *    documentation and/or other materials provided with the distribution.
16
 * 3. All advertising materials mentioning features or use of this software
17
 *    must display the following acknowledgement:
18
 *      This product includes software developed by the University of
19
 *      California, Berkeley and its contributors.
20
 * 4. Neither the name of the University nor the names of its contributors
21
 *    may be used to endorse or promote products derived from this software
22
 *    without specific prior written permission.
23
 *
24
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34
 * SUCH DAMAGE.
35
 */
36
 
37
#if defined(LIBC_SCCS) && !defined(lint)
38
#if 0
39
static char sccsid[] = "@(#)fgetln.c    8.2 (Berkeley) 1/2/94";
40
#endif
41
static const char rcsid[] =
42
                "$\Id: fgetln.c,v 1.3 1996/06/22 10:33:08 jraynard Exp $";
43
#endif /* LIBC_SCCS and not lint */
44
 
45
#include <stdio.h>
46
#include <stdlib.h>
47
#include <string.h>
48
#include "local.h"
49
 
50
/*
51
 * Expand the line buffer.  Return -1 on error.
52
#ifdef notdef
53
 * The `new size' does not account for a terminating '\0',
54
 * so we add 1 here.
55
#endif
56
 */
57
int
58
__slbexpand(fp, newsize)
59
        FILE *fp;
60
        size_t newsize;
61
{
62
        void *p;
63
 
64
#ifdef notdef
65
        ++newsize;
66
#endif
67
        if (fp->_lb._size >= newsize)
68
                return (0);
69
        if ((p = realloc(fp->_lb._base, newsize)) == NULL)
70
                return (-1);
71
        fp->_lb._base = p;
72
        fp->_lb._size = newsize;
73
        return (0);
74
}
75
 
76
/*
77
 * Get an input line.  The returned pointer often (but not always)
78
 * points into a stdio buffer.  Fgetln does not alter the text of
79
 * the returned line (which is thus not a C string because it will
80
 * not necessarily end with '\0'), but does allow callers to modify
81
 * it if they wish.  Thus, we set __SMOD in case the caller does.
82
 */
83
char *
84
fgetln(fp, lenp)
85
        register FILE *fp;
86
        size_t *lenp;
87
{
88
        register unsigned char *p;
89
        register size_t len;
90
        size_t off;
91
 
92
        /* make sure there is input */
93
        if (fp->_r <= 0 && __srefill(fp)) {
94
                *lenp = 0;
95
                return (NULL);
96
        }
97
 
98
        /* look for a newline in the input */
99
        if ((p = memchr((void *)fp->_p, '\n', (size_t)fp->_r)) != NULL) {
100
                register char *ret;
101
 
102
                /*
103
                 * Found one.  Flag buffer as modified to keep fseek from
104
                 * `optimising' a backward seek, in case the user stomps on
105
                 * the text.
106
                 */
107
                p++;            /* advance over it */
108
                ret = (char *)fp->_p;
109
                *lenp = len = p - fp->_p;
110
                fp->_flags |= __SMOD;
111
                fp->_r -= len;
112
                fp->_p = p;
113
                return (ret);
114
        }
115
 
116
        /*
117
         * We have to copy the current buffered data to the line buffer.
118
         * As a bonus, though, we can leave off the __SMOD.
119
         *
120
         * OPTIMISTIC is length that we (optimistically) expect will
121
         * accomodate the `rest' of the string, on each trip through the
122
         * loop below.
123
         */
124
#define OPTIMISTIC 80
125
 
126
        for (len = fp->_r, off = 0;; len += fp->_r) {
127
                register size_t diff;
128
 
129
                /*
130
                 * Make sure there is room for more bytes.  Copy data from
131
                 * file buffer to line buffer, refill file and look for
132
                 * newline.  The loop stops only when we find a newline.
133
                 */
134
                if (__slbexpand(fp, len + OPTIMISTIC))
135
                        goto error;
136
                (void)memcpy((void *)(fp->_lb._base + off), (void *)fp->_p,
137
                    len - off);
138
                off = len;
139
                if (__srefill(fp))
140
                        break;  /* EOF or error: return partial line */
141
                if ((p = memchr((void *)fp->_p, '\n', (size_t)fp->_r)) == NULL)
142
                        continue;
143
 
144
                /* got it: finish up the line (like code above) */
145
                p++;
146
                diff = p - fp->_p;
147
                len += diff;
148
                if (__slbexpand(fp, len))
149
                        goto error;
150
                (void)memcpy((void *)(fp->_lb._base + off), (void *)fp->_p,
151
                    diff);
152
                fp->_r -= diff;
153
                fp->_p = p;
154
                break;
155
        }
156
        *lenp = len;
157
#ifdef notdef
158
        fp->_lb._base[len] = 0;
159
#endif
160
        return ((char *)fp->_lb._base);
161
 
162
error:
163
        *lenp = 0;              /* ??? */
164
        return (NULL);          /* ??? */
165
}