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