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Member "gcal-4.1/lib/lseek.c" (22 Jan 2017, 1819 Bytes) of package /linux/misc/gcal-4.1.tar.gz:


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    1 /* An lseek() function that detects pipes.
    2    Copyright (C) 2007, 2009-2017 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 
   35 off_t
   36 rpl_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 }