1/* getdelim.c --- Implementation of replacement getdelim function.
2 Copyright (C) 1994, 1996-1998, 2001, 2003, 2005-2012 Free Software
3 Foundation, Inc.
4
5 This program is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 2.1, or (at
8 your option) any later version.
9
10 This program is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public License
16 along with this program; if not, see <http://www.gnu.org/licenses/>. */
17
18/* Ported from glibc by Simon Josefsson. */
19
20#include <config.h>
21
22/* Don't use __attribute__ __nonnull__ in this compilation unit. Otherwise gcc
23 optimizes away the lineptr == NULL || n == NULL || fp == NULL tests below. */
24#define _GL_ARG_NONNULL(params)
25
26#include <stdio.h>
27
28#include <limits.h>
29#include <stdint.h>
30#include <stdlib.h>
31#include <errno.h>
32
33#ifndef SSIZE_MAX
34# define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2))
35#endif
36
37#if USE_UNLOCKED_IO
38# include "unlocked-io.h"
39# define getc_maybe_unlocked(fp) getc(fp)
40#elif !HAVE_FLOCKFILE || !HAVE_FUNLOCKFILE || !HAVE_DECL_GETC_UNLOCKED
41# undef flockfile
42# undef funlockfile
43# define flockfile(x) ((void) 0)
44# define funlockfile(x) ((void) 0)
45# define getc_maybe_unlocked(fp) getc(fp)
46#else
47# define getc_maybe_unlocked(fp) getc_unlocked(fp)
48#endif
49
50/* Read up to (and including) a DELIMITER from FP into *LINEPTR (and
51 NUL-terminate it). *LINEPTR is a pointer returned from malloc (or
52 NULL), pointing to *N characters of space. It is realloc'ed as
53 necessary. Returns the number of characters read (not including
54 the null terminator), or -1 on error or EOF. */
55
56ssize_t
57getdelim (char **lineptr, size_t *n, int delimiter, FILE *fp)
58{
59 ssize_t result;
60 size_t cur_len = 0;
61
62 if (lineptr == NULL || n == NULL || fp == NULL)
63 {
64 errno = EINVAL;
65 return -1;
66 }
67
68 flockfile (fp);
69
70 if (*lineptr == NULL || *n == 0)
71 {
72 char *new_lineptr;
73 *n = 120;
74 new_lineptr = (char *) realloc (*lineptr, *n);
75 if (new_lineptr == NULL)
76 {
77 result = -1;
78 goto unlock_return;
79 }
80 *lineptr = new_lineptr;
81 }
82
83 for (;;)
84 {
85 int i;
86
87 i = getc_maybe_unlocked (fp);
88 if (i == EOF)
89 {
90 result = -1;
91 break;
92 }
93
94 /* Make enough space for len+1 (for final NUL) bytes. */
95 if (cur_len + 1 >= *n)
96 {
97 size_t needed_max =
98 SSIZE_MAX < SIZE_MAX ? (size_t) SSIZE_MAX + 1 : SIZE_MAX;
99 size_t needed = 2 * *n + 1; /* Be generous. */
100 char *new_lineptr;
101
102 if (needed_max < needed)
103 needed = needed_max;
104 if (cur_len + 1 >= needed)
105 {
106 result = -1;
107 errno = EOVERFLOW;
108 goto unlock_return;
109 }
110
111 new_lineptr = (char *) realloc (*lineptr, needed);
112 if (new_lineptr == NULL)
113 {
114 result = -1;
115 goto unlock_return;
116 }
117
118 *lineptr = new_lineptr;
119 *n = needed;
120 }
121
122 (*lineptr)[cur_len] = i;
123 cur_len++;
124
125 if (i == delimiter)
126 break;
127 }
128 (*lineptr)[cur_len] = '\0';
129 result = cur_len ? cur_len : result;
130
131 unlock_return:
132 funlockfile (fp); /* doesn't set errno */
133
134 return result;
135}
136