86 lines
2.4 KiB
C
86 lines
2.4 KiB
C
/* An ftello() function that works around platform bugs.
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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 of the License, or
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(at your option) 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
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along 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 <stdio.h>
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/* Get lseek. */
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#include <unistd.h>
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#include "stdio-impl.h"
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off_t
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ftello (FILE *fp)
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#undef ftello
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#if !HAVE_FTELLO
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# undef ftell
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# define ftello ftell
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#endif
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#if _GL_WINDOWS_64_BIT_OFF_T
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# undef ftello
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# if HAVE__FTELLI64 /* msvc, mingw64 */
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# define ftello _ftelli64
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# else /* mingw */
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# define ftello ftello64
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# endif
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#endif
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{
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#if LSEEK_PIPE_BROKEN
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/* mingw gives bogus answers rather than failure on non-seekable files. */
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if (lseek (fileno (fp), 0, SEEK_CUR) == -1)
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return -1;
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#endif
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#if FTELLO_BROKEN_AFTER_SWITCHING_FROM_READ_TO_WRITE /* Solaris */
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/* The Solaris stdio leaves the _IOREAD flag set after reading from a file
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reaches EOF and the program then starts writing to the file. ftello
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gets confused by this. */
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if (fp_->_flag & _IOWRT)
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{
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off_t pos;
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/* Call ftello nevertheless, for the side effects that it does on fp. */
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ftello (fp);
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/* Compute the file position ourselves. */
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pos = lseek (fileno (fp), (off_t) 0, SEEK_CUR);
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if (pos >= 0)
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{
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if ((fp_->_flag & _IONBF) == 0 && fp_->_base != NULL)
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pos += fp_->_ptr - fp_->_base;
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}
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return pos;
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}
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#endif
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#if defined __SL64 && defined __SCLE /* Cygwin */
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if ((fp->_flags & __SL64) == 0)
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{
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/* Cygwin 1.5.0 through 1.5.24 failed to open stdin in 64-bit
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mode; but has an ftello that requires 64-bit mode. */
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FILE *tmp = fopen ("/dev/null", "r");
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if (!tmp)
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return -1;
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fp->_flags |= __SL64;
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fp->_seek64 = tmp->_seek64;
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fclose (tmp);
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}
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#endif
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return ftello (fp);
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}
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