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04277e02 | 1 | /* Copyright (C) 1993-2019 Free Software Foundation, Inc. |
553cc5f9 UD |
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 | |
59ba27a6 | 15 | License along with the GNU C Library; if not, see |
5a82c748 | 16 | <https://www.gnu.org/licenses/>. |
553cc5f9 UD |
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 | #include <stdio.h> | |
29 | #include <sys/param.h> | |
30 | ||
31 | char * | |
9964a145 | 32 | __fgets_chk (char *buf, size_t size, int n, FILE *fp) |
553cc5f9 | 33 | { |
9964a145 | 34 | size_t count; |
553cc5f9 UD |
35 | char *result; |
36 | CHECK_FILE (fp, NULL); | |
37 | if (n <= 0) | |
38 | return NULL; | |
39 | _IO_acquire_lock (fp); | |
40 | /* This is very tricky since a file descriptor may be in the | |
41 | non-blocking mode. The error flag doesn't mean much in this | |
42 | case. We return an error only when there is a new error. */ | |
df6c012b ZW |
43 | int old_error = fp->_flags & _IO_ERR_SEEN; |
44 | fp->_flags &= ~_IO_ERR_SEEN; | |
d18ea0c5 | 45 | count = _IO_getline (fp, buf, MIN ((size_t) n - 1, size), '\n', 1); |
553cc5f9 UD |
46 | /* If we read in some bytes and errno is EAGAIN, that error will |
47 | be reported for next read. */ | |
df6c012b | 48 | if (count == 0 || ((fp->_flags & _IO_ERR_SEEN) && errno != EAGAIN)) |
553cc5f9 UD |
49 | result = NULL; |
50 | else if (count >= size) | |
51 | __chk_fail (); | |
52 | else | |
53 | { | |
54 | buf[count] = '\0'; | |
55 | result = buf; | |
56 | } | |
df6c012b | 57 | fp->_flags |= old_error; |
553cc5f9 UD |
58 | _IO_release_lock (fp); |
59 | return result; | |
60 | } |