diff options
Diffstat (limited to 'lib/ftello.c')
-rw-r--r-- | lib/ftello.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/lib/ftello.c b/lib/ftello.c new file mode 100644 index 0000000..fbdc44f --- /dev/null +++ b/lib/ftello.c @@ -0,0 +1,77 @@ +/* An ftello() function that works around platform bugs. + Copyright (C) 2007, 2009-2011 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +#include <config.h> + +/* Specification. */ +#include <stdio.h> + +/* Get lseek. */ +#include <unistd.h> + +#include "stdio-impl.h" + +off_t +ftello (FILE *fp) +#undef ftello +#if !HAVE_FTELLO +# undef ftell +# define ftello ftell +#endif +{ +#if LSEEK_PIPE_BROKEN + /* mingw gives bogus answers rather than failure on non-seekable files. */ + if (lseek (fileno (fp), 0, SEEK_CUR) == -1) + return -1; +#endif + +#if FTELLO_BROKEN_AFTER_SWITCHING_FROM_READ_TO_WRITE /* Solaris */ + /* The Solaris stdio leaves the _IOREAD flag set after reading from a file + reaches EOF and the program then starts writing to the file. ftello + gets confused by this. */ + if (fp_->_flag & _IOWRT) + { + off_t pos; + + /* Call ftello nevertheless, for the side effects that it does on fp. */ + ftello (fp); + + /* Compute the file position ourselves. */ + pos = lseek (fileno (fp), (off_t) 0, SEEK_CUR); + if (pos >= 0) + { + if ((fp_->_flag & _IONBF) == 0 && fp_->_base != NULL) + pos += fp_->_ptr - fp_->_base; + } + return pos; + } +#endif + +#if defined __SL64 && defined __SCLE /* Cygwin */ + if ((fp->_flags & __SL64) == 0) + { + /* Cygwin 1.5.0 through 1.5.24 failed to open stdin in 64-bit + mode; but has an ftello that requires 64-bit mode. */ + FILE *tmp = fopen ("/dev/null", "r"); + if (!tmp) + return -1; + fp->_flags |= __SL64; + fp->_seek64 = tmp->_seek64; + fclose (tmp); + } +#endif + return ftello (fp); +} |