1 /* An fseeko() function that, together with fflush(), is POSIX compliant.
2 Copyright (C) 2007-2010 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 Lesser General Public License as published by
6 the Free Software Foundation; either version 2.1, 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 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser 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. */
26 #include "stdio-impl.h"
29 fseeko (FILE *fp
, off_t offset
, int whence
)
37 /* mingw gives bogus answers rather than failure on non-seekable files. */
38 if (lseek (fileno (fp
), 0, SEEK_CUR
) == -1)
42 /* These tests are based on fpurge.c. */
43 #if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */
44 if (fp
->_IO_read_end
== fp
->_IO_read_ptr
45 && fp
->_IO_write_ptr
== fp
->_IO_write_base
46 && fp
->_IO_save_base
== NULL
)
47 #elif defined __sferror || defined __DragonFly__ /* FreeBSD, NetBSD, OpenBSD, DragonFly, MacOS X, Cygwin */
48 # if defined __SL64 && defined __SCLE /* Cygwin */
49 if ((fp
->_flags
& __SL64
) == 0)
51 /* Cygwin 1.5.0 through 1.5.24 failed to open stdin in 64-bit
52 mode; but has an fseeko that requires 64-bit mode. */
53 FILE *tmp
= fopen ("/dev/null", "r");
57 fp
->_seek64
= tmp
->_seek64
;
61 if (fp_
->_p
== fp_
->_bf
._base
63 && fp_
->_w
== ((fp_
->_flags
& (__SLBF
| __SNBF
| __SRD
)) == 0 /* fully buffered and not currently reading? */
66 && fp_ub
._base
== NULL
)
67 #elif defined __EMX__ /* emx+gcc */
68 if (fp
->_ptr
== fp
->_buffer
71 && fp
->_ungetc_count
== 0)
72 #elif defined _IOERR /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, mingw */
73 if (fp_
->_ptr
== fp_
->_base
74 && (fp_
->_ptr
== NULL
|| fp_
->_cnt
== 0))
75 #elif defined __UCLIBC__ /* uClibc */
76 if (((fp
->__modeflags
& __FLAG_WRITING
) == 0
77 || fp
->__bufpos
== fp
->__bufstart
)
78 && ((fp
->__modeflags
& (__FLAG_READONLY
| __FLAG_READING
)) == 0
79 || fp
->__bufpos
== fp
->__bufread
))
80 #elif defined __QNX__ /* QNX */
81 if ((fp
->_Mode
& 0x2000 /* _MWRITE */ ? fp
->_Next
== fp
->_Buf
: fp
->_Next
== fp
->_Rend
)
82 && fp
->_Rback
== fp
->_Back
+ sizeof (fp
->_Back
)
83 && fp
->_Rsave
== NULL
)
84 #elif defined __MINT__ /* Atari FreeMiNT */
85 if (fp
->__bufp
== fp
->__buffer
86 && fp
->__get_limit
== fp
->__bufp
87 && fp
->__put_limit
== fp
->__bufp
88 && !fp
->__pushed_back
)
90 #error "Please port gnulib fseeko.c to your platform! Look at the code in fpurge.c, then report this to bug-gnulib."
93 /* We get here when an fflush() call immediately preceded this one. We
94 know there are no buffers.
95 POSIX requires us to modify the file descriptor's position.
96 But we cannot position beyond end of file here. */
99 whence
== SEEK_END
&& offset
> 0 ? 0 : offset
,
103 #if defined __sferror || defined __DragonFly__ /* FreeBSD, NetBSD, OpenBSD, DragonFly, MacOS X, Cygwin */
104 fp_
->_flags
&= ~__SOFF
;
109 #if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */
110 fp
->_flags
&= ~_IO_EOF_SEEN
;
111 #elif defined __sferror || defined __DragonFly__ /* FreeBSD, NetBSD, OpenBSD, DragonFly, MacOS X, Cygwin */
112 # if defined __CYGWIN__
113 /* fp_->_offset is typed as an integer. */
116 /* fp_->_offset is an fpos_t. */
118 /* Use a union, since on NetBSD, the compilation flags
119 determine whether fpos_t is typedef'd to off_t or a struct
120 containing a single off_t member. */
130 fp_
->_flags
|= __SOFF
;
131 fp_
->_flags
&= ~__SEOF
;
132 #elif defined __EMX__ /* emx+gcc */
133 fp
->_flags
&= ~_IOEOF
;
134 #elif defined _IOERR /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, mingw */
135 fp
->_flag
&= ~_IOEOF
;
136 #elif defined __MINT__ /* Atari FreeMiNT */
140 /* If we were not requested to position beyond end of file, we're
142 if (!(whence
== SEEK_END
&& offset
> 0))
145 return fseeko (fp
, offset
, whence
);