72 lines
1.9 KiB
C
72 lines
1.9 KiB
C
/* An lseek() function that detects pipes.
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Copyright (C) 2007, 2009-2020 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License along
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with this program; if not, see <https://www.gnu.org/licenses/>. */
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#include <config.h>
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/* Specification. */
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#include <unistd.h>
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#if defined _WIN32 && ! defined __CYGWIN__
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/* Windows platforms. */
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/* Get GetFileType. */
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# include <windows.h>
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/* Get _get_osfhandle. */
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# if GNULIB_MSVC_NOTHROW
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# include "msvc-nothrow.h"
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# else
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# include <io.h>
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# endif
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#else
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# include <sys/stat.h>
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#endif
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#include <errno.h>
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#undef lseek
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off_t
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rpl_lseek (int fd, off_t offset, int whence)
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{
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#if defined _WIN32 && ! defined __CYGWIN__
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/* mingw lseek mistakenly succeeds on pipes, sockets, and terminals. */
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HANDLE h = (HANDLE) _get_osfhandle (fd);
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if (h == INVALID_HANDLE_VALUE)
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{
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errno = EBADF;
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return -1;
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}
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if (GetFileType (h) != FILE_TYPE_DISK)
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{
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errno = ESPIPE;
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return -1;
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}
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#else
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/* BeOS lseek mistakenly succeeds on pipes... */
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struct stat statbuf;
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if (fstat (fd, &statbuf) < 0)
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return -1;
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if (!S_ISREG (statbuf.st_mode))
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{
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errno = ESPIPE;
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return -1;
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}
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#endif
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#if _GL_WINDOWS_64_BIT_OFF_T || (defined __MINGW32__ && defined _FILE_OFFSET_BITS && (_FILE_OFFSET_BITS == 64))
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return _lseeki64 (fd, offset, whence);
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#else
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return lseek (fd, offset, whence);
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#endif
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}
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