1 /* safe-fgets.c --- like fgets, but allocates its own static buffer.
2
3 Copyright (C) 2005-2013 Free Software Foundation, Inc.
4 Contributed by Red Hat, Inc.
5
6 This file is part of the GNU simulators.
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20
21
22 #include <stdio.h>
23 #include <stdlib.h>
24
25 #include "safe-fgets.h"
26
27 static char *line_buf = 0;
28 static int line_buf_size = 0;
29
30 #define LBUFINCR 100
31
32 char *
safe_fgets(FILE * f)33 safe_fgets (FILE * f)
34 {
35 char *line_ptr;
36
37 if (line_buf == 0)
38 {
39 line_buf = (char *) malloc (LBUFINCR);
40 line_buf_size = LBUFINCR;
41 }
42
43 /* points to last byte */
44 line_ptr = line_buf + line_buf_size - 1;
45
46 /* so we can see if fgets put a 0 there */
47 *line_ptr = 1;
48 if (fgets (line_buf, line_buf_size, f) == 0)
49 return 0;
50
51 /* we filled the buffer? */
52 while (line_ptr[0] == 0 && line_ptr[-1] != '\n')
53 {
54 /* Make the buffer bigger and read more of the line */
55 line_buf_size += LBUFINCR;
56 line_buf = (char *) realloc (line_buf, line_buf_size);
57
58 /* points to last byte again */
59 line_ptr = line_buf + line_buf_size - 1;
60 /* so we can see if fgets put a 0 there */
61 *line_ptr = 1;
62
63 if (fgets (line_buf + line_buf_size - LBUFINCR - 1, LBUFINCR + 1, f) ==
64 0)
65 return 0;
66 }
67
68 return line_buf;
69 }
70