1 /* An fseeko() function that, together with fflush(), is POSIX compliant.
2 Copyright (C) 2007 Free Software Foundation, Inc.
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 2, or (at your option)
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.
14 You should have received a copy of the GNU General Public License along
15 with this program; if not, write to the Free Software Foundation,
16 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
23 /* Get off_t and lseek. */
33 rpl_fseeko (FILE *fp
, off_t offset
, int whence
)
36 /* mingw gives bogus answers rather than failure on non-seekable files. */
37 if (lseek (fileno (fp
), 0, SEEK_CUR
) == -1)
41 /* These tests are based on fpurge.c. */
42 #if defined _IO_ferror_unlocked /* GNU libc, BeOS */
43 if (fp
->_IO_read_end
== fp
->_IO_read_ptr
44 && fp
->_IO_write_ptr
== fp
->_IO_write_base
45 && fp
->_IO_save_base
== NULL
)
46 #elif defined __sferror /* FreeBSD, NetBSD, OpenBSD, MacOS X, Cygwin */
47 # if defined __NetBSD__ || defined __OpenBSD__ /* NetBSD, OpenBSD */
48 /* See <http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libc/stdio/fileext.h?rev=HEAD&content-type=text/x-cvsweb-markup>
49 and <http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/stdio/fileext.h?rev=HEAD&content-type=text/x-cvsweb-markup> */
50 # define fp_ub ((struct { struct __sbuf _ub; } *) fp->_ext._base)->_ub
51 # else /* FreeBSD, MacOS X, Cygwin */
52 # define fp_ub fp->_ub
54 # if defined __SL64 && defined __SCLE /* Cygwin */
55 if ((fp
->_flags
& __SL64
) == 0)
57 /* Cygwin 1.5.0 through 1.5.24 failed to open stdin in 64-bit
58 mode; but has an fseeko that requires 64-bit mode. */
59 FILE *tmp
= fopen ("/dev/null", "r");
63 fp
->_seek64
= tmp
->_seek64
;
67 if (fp
->_p
== fp
->_bf
._base
69 && fp
->_w
== ((fp
->_flags
& (__SLBF
| __SNBF
| __SRD
)) == 0 /* fully buffered and not currently reading? */
72 && fp_ub
._base
== NULL
)
73 #elif defined _IOERR /* AIX, HP-UX, IRIX, OSF/1, Solaris, mingw */
74 # if defined __sun && defined __sparc && defined _LP64 /* Solaris/SPARC 64-bit */
75 # define fp_ ((struct { unsigned char *_ptr; \
76 unsigned char *_base; \
77 unsigned char *_end; \
80 if (fp_
->_ptr
== fp_
->_base
81 && (fp_
->_ptr
== NULL
|| fp_
->_cnt
== 0))
83 if (fp
->_ptr
== fp
->_base
84 && (fp
->_ptr
== NULL
|| fp
->_cnt
== 0))
86 #elif defined __UCLIBC__ /* uClibc */
87 if (((fp
->__modeflags
& __FLAG_WRITING
) == 0
88 || fp
->__bufpos
== fp
->__bufstart
)
89 && ((fp
->__modeflags
& (__FLAG_READONLY
| __FLAG_READING
)) == 0
90 || fp
->__bufpos
== fp
->__bufread
))
92 #error "Please port gnulib fseeko.c to your platform! Look at the code in fpurge.c, then report this to bug-gnulib."
95 off_t pos
= lseek (fileno (fp
), offset
, whence
);
98 #if defined __sferror /* FreeBSD, NetBSD, OpenBSD, MacOS X, Cygwin */
99 fp
->_flags
&= ~__SOFF
;
105 #if defined __sferror /* FreeBSD, NetBSD, OpenBSD, MacOS X, Cygwin */
107 fp
->_flags
|= __SOFF
;
113 return fseeko (fp
, offset
, whence
);