1 files changed, 63 insertions, 0 deletions
diff --git a/lib/fpending.c b/lib/fpending.c
new file mode 100644
index 0000000..e57155e
--- /dev/null
+++ b/lib/fpending.c
@@ -0,0 +1,63 @@
+/* fpending.c -- return the number of pending output bytes on a stream
+   Copyright (C) 2000, 2004, 2006-2007, 2009-2023 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 <https://www.gnu.org/licenses/>.  */
+
+/* Written by Jim Meyering. */
+
+#include <config.h>
+
+/* Specification.  */
+#include "fpending.h"
+
+#include "stdio-impl.h"
+
+/* This file is not used on systems that already have the __fpending function,
+   namely glibc >= 2.2, Solaris >= 7, UnixWare >= 7.1.4.MP4, Cygwin >= 1.7.34,
+   Android API >= 23.  */
+
+/* Return the number of pending (aka buffered, unflushed)
+   bytes on the stream, FP, that is open for writing.  */
+size_t
+__fpending (FILE *fp)
+{
+  /* Most systems provide FILE as a struct and the necessary bitmask in
+     <stdio.h>, because they need it for implementing getc() and putc() as
+     fast macros.  */
+#if defined _IO_EOF_SEEN || defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1
+  /* GNU libc, BeOS, Haiku, Linux libc5 */
+  return fp->_IO_write_ptr - fp->_IO_write_base;
+#elif defined __sferror || defined __DragonFly__ || defined __ANDROID__
+  /* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin < 1.7.34, Minix 3, Android */
+  return fp_->_p - fp_->_bf._base;
+#elif defined __EMX__                /* emx+gcc */
+  return fp->_ptr - fp->_buffer;
+#elif defined __minix                /* Minix */
+  return fp_->_ptr - fp_->_buf;
+#elif defined _IOERR                 /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, UnixWare, mingw, MSVC, NonStop Kernel, OpenVMS */
+  return (fp_->_ptr ? fp_->_ptr - fp_->_base : 0);
+#elif defined __UCLIBC__             /* uClibc */
+  return (fp->__modeflags & __FLAG_WRITING ? fp->__bufpos - fp->__bufstart : 0);
+#elif defined __QNX__                /* QNX */
+  return (fp->_Mode & 0x2000 /*_MWRITE*/ ? fp->_Next - fp->_Buf : 0);
+#elif defined __MINT__               /* Atari FreeMiNT */
+  return fp->__bufp - fp->__buffer;
+#elif defined EPLAN9                 /* Plan9 */
+  return fp->wp - fp->buf;
+#else
+# error "Please port gnulib fpending.c to your platform!"
+  return 1;
+#endif
+}