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
|
/* getndelim2 - Read a line from a stream, stopping at one of 2 delimiters,
with bounded memory allocation.
Copyright (C) 1993, 1996, 1997, 1998, 2000, 2003, 2004 Free Software
Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
/* Originally written by Jan Brittenson, bson@gnu.ai.mit.edu. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include "getndelim2.h"
#include <stdlib.h>
#include <stddef.h>
#if USE_UNLOCKED_IO
# include "unlocked-io.h"
#endif
#include <limits.h>
#if HAVE_INTTYPES_H
# include <inttypes.h>
#endif
#if HAVE_STDINT_H
# include <stdint.h>
#endif
#ifndef PTRDIFF_MAX
# define PTRDIFF_MAX ((ptrdiff_t) (SIZE_MAX / 2))
#endif
#ifndef SIZE_MAX
# define SIZE_MAX ((size_t) -1)
#endif
#ifndef SSIZE_MAX
# define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2))
#endif
/* The maximum value that getndelim2 can return without suffering from
overflow problems, either internally (because of pointer
subtraction overflow) or due to the API (because of ssize_t). */
#define GETNDELIM2_MAXIMUM (PTRDIFF_MAX < SSIZE_MAX ? PTRDIFF_MAX : SSIZE_MAX)
/* Try to add at least this many bytes when extending the buffer.
MIN_CHUNK must be no greater than GETNDELIM2_MAXIMUM. */
#define MIN_CHUNK 64
ssize_t
getndelim2 (char **lineptr, size_t *linesize, size_t offset, size_t nmax,
int delim1, int delim2, FILE *stream)
{
size_t nbytes_avail; /* Allocated but unused bytes in *LINEPTR. */
char *read_pos; /* Where we're reading into *LINEPTR. */
ssize_t bytes_stored = -1;
char *ptr = *lineptr;
size_t size = *linesize;
if (!ptr)
{
size = nmax < MIN_CHUNK ? nmax : MIN_CHUNK;
ptr = malloc (size);
if (!ptr)
return -1;
}
if (size < offset)
goto done;
nbytes_avail = size - offset;
read_pos = ptr + offset;
if (nbytes_avail == 0 && nmax <= size)
goto done;
for (;;)
{
/* Here always ptr + size == read_pos + nbytes_avail. */
int c;
/* We always want at least one byte left in the buffer, since we
always (unless we get an error while reading the first byte)
NUL-terminate the line buffer. */
if (nbytes_avail < 2 && size < nmax)
{
size_t newsize = size < MIN_CHUNK ? size + MIN_CHUNK : 2 * size;
char *newptr;
if (! (size < newsize && newsize <= nmax))
newsize = nmax;
if (GETNDELIM2_MAXIMUM < newsize - offset)
{
size_t newsizemax = offset + GETNDELIM2_MAXIMUM + 1;
if (size == newsizemax)
goto done;
newsize = newsizemax;
}
nbytes_avail = newsize - (read_pos - ptr);
newptr = realloc (ptr, newsize);
if (!newptr)
goto done;
ptr = newptr;
size = newsize;
read_pos = size - nbytes_avail + ptr;
}
c = getc (stream);
if (c == EOF)
{
/* Return partial line, if any. */
if (read_pos == ptr)
goto done;
else
break;
}
if (nbytes_avail >= 2)
{
*read_pos++ = c;
nbytes_avail--;
}
if (c == delim1 || c == delim2)
/* Return the line. */
break;
}
/* Done - NUL terminate and return the number of bytes read.
At this point we know that nbytes_avail >= 1. */
*read_pos = '\0';
bytes_stored = read_pos - (ptr + offset);
done:
*lineptr = ptr;
*linesize = size;
return bytes_stored;
}
|
