Mercurial > hg > octave-nkf > gnulib-hg
annotate lib/pread.c @ 17907:0a1c2535cad9
euidaccess: Fix Android build
* modules/euidaccess (Depends-on): Add fcntl-h to ensure that
AT_EACCESS gets declared.
| author | Kevin Cernekee <cernekee@google.com> |
|---|---|
| date | Wed, 11 Feb 2015 15:22:54 -0800 |
| parents | ab58d4870664 |
| children |
| rev | line source |
|---|---|
| 12355 | 1 /* replacement pread function |
| 17848 | 2 Copyright (C) 2009-2015 Free Software Foundation, Inc. |
| 12355 | 3 |
| 4 This program is free software: you can redistribute it and/or modify | |
| 5 it under the terms of the GNU General Public License as published by | |
| 6 the Free Software Foundation; either version 3 of the License, or | |
| 7 (at your option) any later version. | |
| 8 | |
| 9 This program 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 | |
| 12 GNU General Public License for more details. | |
| 13 | |
| 14 You should have received a copy of the GNU General Public License | |
| 15 along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
| 16 | |
| 17 #include <config.h> | |
| 18 | |
| 19 /* Specification. */ | |
| 20 #include <unistd.h> | |
| 21 | |
| 22 #include <errno.h> | |
| 23 | |
| 24 #define __libc_lseek(f,o,w) lseek (f, o, w) | |
| 25 #define __set_errno(Val) errno = (Val) | |
|
12362
7d728682ee08
pread: improvement and fix
Jim Meyering <meyering@redhat.com>
parents:
12355
diff
changeset
|
26 #define __libc_read(f,b,n) read (f, b, n) |
| 12355 | 27 |
| 28 /* pread substitute for systems that the function, such as mingw32 and BeOS. */ | |
| 29 /* The following is identical to the function from glibc's | |
| 30 sysdeps/posix/pread.c */ | |
| 31 | |
| 32 /* Note: This implementation of pread is not multithread-safe. */ | |
| 33 | |
| 34 ssize_t | |
| 35 pread (int fd, void *buf, size_t nbyte, off_t offset) | |
| 36 { | |
| 37 /* Since we must not change the file pointer preserve the value so that | |
| 38 we can restore it later. */ | |
| 39 int save_errno; | |
| 40 ssize_t result; | |
| 41 off_t old_offset = __libc_lseek (fd, 0, SEEK_CUR); | |
| 42 if (old_offset == (off_t) -1) | |
| 43 return -1; | |
| 44 | |
| 45 /* Set to wanted position. */ | |
| 46 if (__libc_lseek (fd, offset, SEEK_SET) == (off_t) -1) | |
| 47 return -1; | |
| 48 | |
| 49 /* Write out the data. */ | |
| 50 result = __libc_read (fd, buf, nbyte); | |
| 51 | |
| 52 /* Now we have to restore the position. If this fails we have to | |
| 53 return this as an error. But if the writing also failed we | |
| 54 return this error. */ | |
| 55 save_errno = errno; | |
| 56 if (__libc_lseek (fd, old_offset, SEEK_SET) == (off_t) -1) | |
| 57 { | |
| 58 if (result == -1) | |
|
12421
e8d2c6fc33ad
Use spaces for indentation, not tabs.
Bruno Haible <bruno@clisp.org>
parents:
12362
diff
changeset
|
59 __set_errno (save_errno); |
| 12355 | 60 return -1; |
| 61 } | |
| 62 __set_errno (save_errno); | |
| 63 | |
| 64 return result; | |
| 65 } |