1/* An lseek() function that detects pipes. 2 Copyright (C) 2007, 2009-2014 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, see <http://www.gnu.org/licenses/>. */ 16 17#include <config.h> 18 19/* Specification. */ 20#include <unistd.h> 21 22#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ 23/* Windows platforms. */ 24/* Get GetFileType. */ 25# include <windows.h> 26/* Get _get_osfhandle. */ 27# include "msvc-nothrow.h" 28#else 29# include <sys/stat.h> 30#endif 31#include <errno.h> 32 33#undef lseek 34 35off_t 36rpl_lseek (int fd, off_t offset, int whence) 37{ 38#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ 39 /* mingw lseek mistakenly succeeds on pipes, sockets, and terminals. */ 40 HANDLE h = (HANDLE) _get_osfhandle (fd); 41 if (h == INVALID_HANDLE_VALUE) 42 { 43 errno = EBADF; 44 return -1; 45 } 46 if (GetFileType (h) != FILE_TYPE_DISK) 47 { 48 errno = ESPIPE; 49 return -1; 50 } 51#else 52 /* BeOS lseek mistakenly succeeds on pipes... */ 53 struct stat statbuf; 54 if (fstat (fd, &statbuf) < 0) 55 return -1; 56 if (!S_ISREG (statbuf.st_mode)) 57 { 58 errno = ESPIPE; 59 return -1; 60 } 61#endif 62#if _GL_WINDOWS_64_BIT_OFF_T 63 return _lseeki64 (fd, offset, whence); 64#else 65 return lseek (fd, offset, whence); 66#endif 67} 68