1/* An fseeko() function that, together with fflush(), is POSIX compliant. 2 Copyright (C) 2007 Free Software Foundation, Inc. 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, or (at your option) 7 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 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. */ 17 18#include <config.h> 19 20/* Specification. */ 21#include <stdio.h> 22 23/* Get off_t and lseek. */ 24#include <unistd.h> 25 26#undef fseeko 27#if !HAVE_FSEEKO 28# undef fseek 29# define fseeko fseek 30#endif 31 32int 33rpl_fseeko (FILE *fp, off_t offset, int whence) 34{ 35#if LSEEK_PIPE_BROKEN 36 /* mingw gives bogus answers rather than failure on non-seekable files. */ 37 if (lseek (fileno (fp), 0, SEEK_CUR) == -1) 38 return EOF; 39#endif 40 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 53# endif 54# if defined __SL64 && defined __SCLE /* Cygwin */ 55 if ((fp->_flags & __SL64) == 0) 56 { 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"); 60 if (!tmp) 61 return -1; 62 fp->_flags |= __SL64; 63 fp->_seek64 = tmp->_seek64; 64 fclose (tmp); 65 } 66# endif 67 if (fp->_p == fp->_bf._base 68 && fp->_r == 0 69 && fp->_w == ((fp->_flags & (__SLBF | __SNBF | __SRD)) == 0 /* fully buffered and not currently reading? */ 70 ? fp->_bf._size 71 : 0) 72 && fp_ub._base == NULL) 73#elif defined _IOERR /* AIX, HP-UX, IRIX, OSF/1, Solaris, mingw */ 74# if defined __sun && defined _LP64 /* Solaris/{SPARC,AMD64} 64-bit */ 75# define fp_ ((struct { unsigned char *_ptr; \ 76 unsigned char *_base; \ 77 unsigned char *_end; \ 78 long _cnt; \ 79 int _file; \ 80 unsigned int _flag; \ 81 } *) fp) 82 if (fp_->_ptr == fp_->_base 83 && (fp_->_ptr == NULL || fp_->_cnt == 0)) 84# else 85 if (fp->_ptr == fp->_base 86 && (fp->_ptr == NULL || fp->_cnt == 0)) 87# endif 88#elif defined __UCLIBC__ /* uClibc */ 89 if (((fp->__modeflags & __FLAG_WRITING) == 0 90 || fp->__bufpos == fp->__bufstart) 91 && ((fp->__modeflags & (__FLAG_READONLY | __FLAG_READING)) == 0 92 || fp->__bufpos == fp->__bufread)) 93#elif defined __QNX__ /* QNX */ 94 if ((fp->_Mode & _MWRITE ? fp->_Next == fp->_Buf : fp->_Next == fp->_Rend) 95 && fp->_Rback == fp->_Back + sizeof (fp->_Back) 96 && fp->_Rsave == NULL) 97#else 98 #error "Please port gnulib fseeko.c to your platform! Look at the code in fpurge.c, then report this to bug-gnulib." 99#endif 100 { 101 off_t pos = lseek (fileno (fp), offset, whence); 102 if (pos == -1) 103 { 104#if defined __sferror /* FreeBSD, NetBSD, OpenBSD, MacOS X, Cygwin */ 105 fp->_flags &= ~__SOFF; 106#endif 107 return -1; 108 } 109 else 110 { 111#if defined __sferror /* FreeBSD, NetBSD, OpenBSD, MacOS X, Cygwin */ 112 fp->_offset = pos; 113 fp->_flags |= __SOFF; 114#endif 115 return 0; 116 } 117 } 118 else 119 return fseeko (fp, offset, whence); 120} 121