| 1 | /* safe-fgets.c --- like fgets, but allocates its own static buffer. |
| 2 | |
| 3 | Copyright (C) 2005-2016 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 * |
| 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 | } |