| 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 "libioP.h" |
| 28 | |
| 29 | #define _IOFBF 0 /* Fully buffered. */ |
| 30 | #define _IOLBF 1 /* Line buffered. */ |
| 31 | #define _IONBF 2 /* No buffering. */ |
| 32 | |
| 33 | int |
| 34 | _IO_setvbuf (_IO_FILE *fp, char *buf, int mode, _IO_size_t size) |
| 35 | { |
| 36 | int result; |
| 37 | CHECK_FILE (fp, EOF); |
| 38 | _IO_acquire_lock (fp); |
| 39 | switch (mode) |
| 40 | { |
| 41 | case _IOFBF: |
| 42 | fp->_IO_file_flags &= ~(_IO_LINE_BUF|_IO_UNBUFFERED); |
| 43 | if (buf == NULL) |
| 44 | { |
| 45 | if (fp->_IO_buf_base == NULL) |
| 46 | { |
| 47 | /* There is no flag to distinguish between "fully buffered |
| 48 | mode has been explicitly set" as opposed to "line |
| 49 | buffering has not been explicitly set". In both |
| 50 | cases, _IO_LINE_BUF is off. If this is a tty, and |
| 51 | _IO_filedoalloc later gets called, it cannot know if |
| 52 | it should set the _IO_LINE_BUF flag (because that is |
| 53 | the default), or not (because we have explicitly asked |
| 54 | for fully buffered mode). So we make sure a buffer |
| 55 | gets allocated now, and explicitly turn off line |
| 56 | buffering. |
| 57 | |
| 58 | A possibly cleaner alternative would be to add an |
| 59 | extra flag, but then flags are a finite resource. */ |
| 60 | if (_IO_DOALLOCATE (fp) < 0) |
| 61 | { |
| 62 | result = EOF; |
| 63 | goto unlock_return; |
| 64 | } |
| 65 | fp->_IO_file_flags &= ~_IO_LINE_BUF; |
| 66 | } |
| 67 | result = 0; |
| 68 | goto unlock_return; |
| 69 | } |
| 70 | break; |
| 71 | case _IOLBF: |
| 72 | fp->_IO_file_flags &= ~_IO_UNBUFFERED; |
| 73 | fp->_IO_file_flags |= _IO_LINE_BUF; |
| 74 | if (buf == NULL) |
| 75 | { |
| 76 | result = 0; |
| 77 | goto unlock_return; |
| 78 | } |
| 79 | break; |
| 80 | case _IONBF: |
| 81 | fp->_IO_file_flags &= ~_IO_LINE_BUF; |
| 82 | fp->_IO_file_flags |= _IO_UNBUFFERED; |
| 83 | buf = NULL; |
| 84 | size = 0; |
| 85 | break; |
| 86 | default: |
| 87 | result = EOF; |
| 88 | goto unlock_return; |
| 89 | } |
| 90 | result = _IO_SETBUF (fp, buf, size) == NULL ? EOF : 0; |
| 91 | |
| 92 | unlock_return: |
| 93 | _IO_release_lock (fp); |
| 94 | return result; |
| 95 | } |
| 96 | libc_hidden_def (_IO_setvbuf) |
| 97 | |
| 98 | #ifdef weak_alias |
| 99 | weak_alias (_IO_setvbuf, setvbuf) |
| 100 | #endif |