| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* Copyright (C) 1993-2016 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. |
| 3 | |
| 4 | The GNU C Library is free software; you can redistribute it and/or |
| 5 | modify it under the terms of the GNU Lesser General Public |
| 6 | License as published by the Free Software Foundation; either |
| 7 | version 2.1 of the License, or (at your option) any later version. |
| 8 | |
| 9 | The GNU C Library is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | Lesser General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU Lesser General Public |
| 15 | License along with the GNU C Library; if not, see |
| 16 | <http://www.gnu.org/licenses/>. |
| 17 | |
| 18 | As a special exception, if you link the code in this file with |
| 19 | files compiled with a GNU compiler to produce an executable, |
| 20 | that does not cause the resulting executable to be covered by |
| 21 | the GNU Lesser General Public License. This exception does not |
| 22 | however invalidate any other reasons why the executable file |
| 23 | might be covered by the GNU Lesser General Public License. |
| 24 | This exception applies to code released by its copyright holders |
| 25 | in files containing the exception. */ |
| 26 | |
| 27 | #include "../libio/libioP.h" |
| 28 | #include <limits.h> |
| 29 | |
| 30 | char * |
| 31 | __gets_chk (char *buf, size_t size) |
| 32 | { |
| 33 | _IO_size_t count; |
| 34 | int ch; |
| 35 | char *retval; |
| 36 | |
| 37 | if (size == 0) |
| 38 | __chk_fail (); |
| 39 | |
| 40 | _IO_acquire_lock (_IO_stdin); |
| 41 | ch = _IO_getc_unlocked (_IO_stdin); |
| 42 | if (ch == EOF) |
| 43 | { |
| 44 | retval = NULL; |
| 45 | goto unlock_return; |
| 46 | } |
| 47 | if (ch == '\n') |
| 48 | count = 0; |
| 49 | else |
| 50 | { |
| 51 | /* This is very tricky since a file descriptor may be in the |
| 52 | non-blocking mode. The error flag doesn't mean much in this |
| 53 | case. We return an error only when there is a new error. */ |
| 54 | int old_error = _IO_stdin->_IO_file_flags & _IO_ERR_SEEN; |
| 55 | _IO_stdin->_IO_file_flags &= ~_IO_ERR_SEEN; |
| 56 | buf[0] = (char) ch; |
| 57 | count = _IO_getline (_IO_stdin, buf + 1, size - 1, '\n', 0) + 1; |
| 58 | if (_IO_stdin->_IO_file_flags & _IO_ERR_SEEN) |
| 59 | { |
| 60 | retval = NULL; |
| 61 | goto unlock_return; |
| 62 | } |
| 63 | else |
| 64 | _IO_stdin->_IO_file_flags |= old_error; |
| 65 | } |
| 66 | if (count >= size) |
| 67 | __chk_fail (); |
| 68 | buf[count] = 0; |
| 69 | retval = buf; |
| 70 | unlock_return: |
| 71 | _IO_release_lock (_IO_stdin); |
| 72 | return retval; |
| 73 | } |
| 74 | |
| 75 | link_warning (__gets_chk, "the `gets' function is dangerous and should not be used.") |