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1 | /* safe-fgets.c --- like fgets, but allocates its own static buffer. |
2 | ||
ecd75fc8 | 3 | Copyright (C) 2005-2014 Free Software Foundation, Inc. |
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4 | Contributed by Red Hat, Inc. |
5 | ||
6 | This file is part of the GNU simulators. | |
7 | ||
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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. | |
d45a4bef | 12 | |
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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. | |
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17 | |
18 | You should have received a copy of the GNU General Public License | |
4744ac1b | 19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
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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 * | |
3877a145 | 33 | safe_fgets (FILE * f) |
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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 | } |