1/* getdelim.c --- Implementation of replacement getdelim function.
2   Copyright (C) 1994, 1996, 1997, 1998, 2001, 2003, 2005, 2006, 2007,
3   2008, 2009 Free Software Foundation, Inc.
4
5   This program is free software; you can redistribute it and/or
6   modify it under the terms of the GNU General Public License as
7   published by the Free Software Foundation; either version 3, 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   General Public License for more details.
14
15   You should have received a copy of the GNU General Public License
16   along with this program; if not, write to the Free Software
17   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18   02110-1301, USA.  */
19
20/* Ported from glibc by Simon Josefsson. */
21
22#include <config.h>
23
24#include <stdio.h>
25
26#include <limits.h>
27#include <stdint.h>
28#include <stdlib.h>
29#include <errno.h>
30
31#ifndef SSIZE_MAX
32# define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2))
33#endif
34
35#if USE_UNLOCKED_IO
36# include "unlocked-io.h"
37# define getc_maybe_unlocked(fp)	getc(fp)
38#elif !HAVE_FLOCKFILE || !HAVE_FUNLOCKFILE || !HAVE_DECL_GETC_UNLOCKED
39# undef flockfile
40# undef funlockfile
41# define flockfile(x) ((void) 0)
42# define funlockfile(x) ((void) 0)
43# define getc_maybe_unlocked(fp)	getc(fp)
44#else
45# define getc_maybe_unlocked(fp)	getc_unlocked(fp)
46#endif
47
48/* Read up to (and including) a DELIMITER from FP into *LINEPTR (and
49   NUL-terminate it).  *LINEPTR is a pointer returned from malloc (or
50   NULL), pointing to *N characters of space.  It is realloc'ed as
51   necessary.  Returns the number of characters read (not including
52   the null terminator), or -1 on error or EOF.  */
53
54ssize_t
55getdelim (char **lineptr, size_t *n, int delimiter, FILE *fp)
56{
57  ssize_t result;
58  size_t cur_len = 0;
59
60  if (lineptr == NULL || n == NULL || fp == NULL)
61    {
62      errno = EINVAL;
63      return -1;
64    }
65
66  flockfile (fp);
67
68  if (*lineptr == NULL || *n == 0)
69    {
70      char *new_lineptr;
71      *n = 120;
72      new_lineptr = (char *) realloc (*lineptr, *n);
73      if (new_lineptr == NULL)
74	{
75	  result = -1;
76	  goto unlock_return;
77	}
78      *lineptr = new_lineptr;
79    }
80
81  for (;;)
82    {
83      int i;
84
85      i = getc_maybe_unlocked (fp);
86      if (i == EOF)
87	{
88	  result = -1;
89	  break;
90	}
91
92      /* Make enough space for len+1 (for final NUL) bytes.  */
93      if (cur_len + 1 >= *n)
94	{
95	  size_t needed_max =
96	    SSIZE_MAX < SIZE_MAX ? (size_t) SSIZE_MAX + 1 : SIZE_MAX;
97	  size_t needed = 2 * *n + 1;   /* Be generous. */
98	  char *new_lineptr;
99
100	  if (needed_max < needed)
101	    needed = needed_max;
102	  if (cur_len + 1 >= needed)
103	    {
104	      result = -1;
105	      errno = EOVERFLOW;
106	      goto unlock_return;
107	    }
108
109	  new_lineptr = (char *) realloc (*lineptr, needed);
110	  if (new_lineptr == NULL)
111	    {
112	      result = -1;
113	      goto unlock_return;
114	    }
115
116	  *lineptr = new_lineptr;
117	  *n = needed;
118	}
119
120      (*lineptr)[cur_len] = i;
121      cur_len++;
122
123      if (i == delimiter)
124	break;
125    }
126  (*lineptr)[cur_len] = '\0';
127  result = cur_len ? cur_len : result;
128
129 unlock_return:
130  funlockfile (fp); /* doesn't set errno */
131
132  return result;
133}
134