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 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, 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 
56 ssize_t
getdelim(char ** lineptr,size_t * n,int delimiter,FILE * fp)57 getdelim (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