* modules/stdio (Makefile.am): Support fflush.
* m4/stdio_h.m4 (gl_STDIO_H_DEFAULTS): Likewise.
* modules/fflush: New file.
* lib/fflush.c: Likewise.
* m4/fflush.m4: Likewise.
* modules/fflush-tests: New test.
* tests/test-fflush.c: Likewise.
* MODULES.html.sh (Input/output <stdio.h>): Document new module.
+2007-04-09 Eric Blake <ebb9@byu.net>
+
+ * lib/stdio_.h [REPLACE_FFLUSH]: Declare rpl_fflush.
+ * modules/stdio (Makefile.am): Support fflush.
+ * m4/stdio_h.m4 (gl_STDIO_H_DEFAULTS): Likewise.
+ * modules/fflush: New file.
+ * lib/fflush.c: Likewise.
+ * m4/fflush.m4: Likewise.
+ * modules/fflush-tests: New test.
+ * tests/test-fflush.c: Likewise.
+ * MODULES.html.sh (Input/output <stdio.h>): Document new module.
+
2007-04-06 Bruno Haible <bruno@clisp.org>
* lib/vasnprintf.c: Include <math.h>. Don't include float+.h.
func_echo "$element"
func_begin_table
+ func_module fflush
func_module fseterr
func_module tmpfile
func_end_table
--- /dev/null
+/* fflush.c -- allow flushing input streams
+ Copyright (C) 2007 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 2, 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, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+/* Written by Eric Blake. */
+
+#include <config.h>
+#include <errno.h>
+#include <stdio.h>
+
+#if HAVE_STDIO_EXT_H
+# include <stdio_ext.h>
+#endif
+
+#if HAVE_FPURGE && ! HAVE_DECL_FPURGE
+int fpurge (FILE *);
+#endif
+
+#undef fflush
+
+/* Flush all pending data on STREAM according to POSIX rules. Both
+ output and seekable input streams are supported. */
+int
+rpl_fflush (FILE *stream)
+{
+ int e1; /* Leave errno unchanged on success. */
+ int e2; /* Capture errno of first fflush if nothing else succeeds. */
+ int result;
+
+ /* Try flushing the stream. C89 guarantees behavior of output
+ streams, so we only need to worry if failure might have been on
+ an input stream. When stream is NULL, POSIX only requires
+ flushing of output streams. */
+ e1 = errno;
+ result = fflush (stream);
+ if (! stream || result == 0 || errno != EBADF)
+ return result;
+
+ /* POSIX does not specify behavior for non-seekable streams. */
+ e2 = errno;
+ if (fseeko (stream, 0, SEEK_CUR) != 0)
+ {
+ errno = e2;
+ return EOF;
+ }
+
+ /* To get here, we must be flushing a seekable input stream, so the
+ semantics of fpurge are now appropriate. */
+#if HAVE_FPURGE
+ errno = e1;
+ result = fpurge (stream);
+#elif HAVE___FPURGE
+ /* __fpurge has no return value, and on Solaris, we can't even trust
+ errno. So assume it succeeds. */
+ __fpurge (stream);
+ result = 0;
+ errno = e1;
+#else /* ! HAVE___FPURGE */
+
+ /* No single replacement; do it manually. */
+ {
+ off_t position = ftello (stream);
+ if (position == -1)
+ {
+ result = EOF; /* Should not happen; we know stream is seekable. */
+ }
+ /* Set position of stream; hopefully the stdio routines don't
+ overoptimize by not setting the underlying file position. */
+ else if (fseeko (stream, position, SEEK_SET) != 0)
+ {
+ result = EOF;
+ errno = e2;
+ }
+ else
+ {
+ result = 0;
+ errno = e1;
+ }
+ }
+#endif /* ! HAVE___FPURGE */
+
+ return result;
+}
# endif
#endif
+#if @GNULIB_FFLUSH@ && @REPLACE_FFLUSH@
+# define fflush rpl_fflush
+ /* Flush all pending data on STREAM according to POSIX rules. Both
+ output and seekable input streams are supported. */
+ extern int fflush (FILE *gl_stream);
+#endif
+
#ifdef __cplusplus
}
#endif
--- /dev/null
+#serial 1
+
+# Copyright (C) 2007 Free Software Foundation, Inc.
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+dnl From Eric Blake
+
+dnl Find out how to obey POSIX semantics of fflush(stdin) discarding
+dnl unread input, rather than C99 undefined semantics. fpurge is not
+dnl standardized, but has the desired properties.
+
+AC_DEFUN([gl_FUNC_FFLUSH],
+[
+ AC_CACHE_CHECK([whether fflush works on input streams],
+ [gl_cv_func_fflush_stdin],
+ [echo hello world > conftest.txt
+ AC_RUN_IFELSE([AC_LANG_PROGRAM(
+ [[
+#include <stdio.h>
+#include <unistd.h>
+ ]], [[FILE *f = fopen ("conftest.txt", "r");
+ char buffer[10];
+ int fd = fileno (f);
+ if (!f || 0 > fd || fread (buffer, 1, 5, f) != 5)
+ return 2;
+ /* For deterministic results, ensure f read a bigger buffer. */
+ if (lseek (fd, 0, SEEK_CUR) == 5)
+ return 3;
+ /* POSIX requires fflush-fseek to set file offset of fd. */
+ if (fflush (f) != 0 || fseek (f, 0, SEEK_CUR) != 0)
+ return 4;
+ return !(lseek (fd, 0, SEEK_CUR) == 5);
+ ]])], [gl_cv_func_fflush_stdin=yes], [gl_cv_func_fflush_stdin=no],
+ [dnl Pessimistically assume fflush is broken. This is wrong for
+ dnl at least glibc and cygwin; but lib/fflush.c takes this into account.
+ gl_cv_func_fflush_stdin=no])
+ rm conftest.txt
+ ])
+ if test $gl_cv_func_fflush_stdin = no; then
+ gl_REPLACE_FFLUSH
+ fi
+])
+
+AC_DEFUN([gl_REPLACE_FFLUSH],
+[
+ AC_CHECK_HEADERS_ONCE([stdio_ext.h])
+ AC_CHECK_FUNCS_ONCE([fpurge __fpurge])
+dnl Linux documents int fpurge(), but only declares void __fpurge().
+ AC_CHECK_DECLS([fpurge], [], [], [[
+#include <stdio.h>
+#if HAVE_STDIO_EXT_H
+# include <stdio_ext.h>
+#endif
+]])
+ AC_LIBOBJ([fflush])
+ AC_REQUIRE([gl_STDIO_H_DEFAULTS])
+ REPLACE_FFLUSH=1
+])
GNULIB_VSNPRINTF=0; AC_SUBST([GNULIB_VSNPRINTF])
GNULIB_VSPRINTF_POSIX=0; AC_SUBST([GNULIB_VSPRINTF_POSIX])
GNULIB_VASPRINTF=0; AC_SUBST([GNULIB_VASPRINTF])
+ GNULIB_FFLUSH=0; AC_SUBST([GNULIB_FFLUSH])
dnl Assume proper GNU behavior unless another module says otherwise.
REPLACE_FPRINTF=0; AC_SUBST([REPLACE_FPRINTF])
REPLACE_VFPRINTF=0; AC_SUBST([REPLACE_VFPRINTF])
REPLACE_VSPRINTF=0; AC_SUBST([REPLACE_VSPRINTF])
HAVE_VASPRINTF=1; AC_SUBST([HAVE_VASPRINTF])
REPLACE_VASPRINTF=0; AC_SUBST([REPLACE_VASPRINTF])
+ REPLACE_FFLUSH=0; AC_SUBST([REPLACE_FFLUSH])
])
--- /dev/null
+Description:
+Discard pending data on both input and output streams.
+
+Files:
+lib/fflush.c
+m4/fflush.m4
+
+Depends-on:
+stdio
+
+configure.ac:
+gl_FUNC_FFLUSH
+gl_STDIO_MODULE_INDICATOR([fflush])
+
+Makefile.am:
+
+Include:
+
+License:
+GPL
+
+Maintainer:
+Eric Blake
--- /dev/null
+Files:
+tests/test-fflush.c
+
+Depends-on:
+unistd
+
+configure.ac:
+
+Makefile.am:
+TESTS += test-fflush
+check_PROGRAMS += test-fflush
+EXTRA_DIST += test-fflush.c
-e 's|@''GNULIB_VSNPRINTF''@|$(GNULIB_VSNPRINTF)|g' \
-e 's|@''GNULIB_VSPRINTF_POSIX''@|$(GNULIB_VSPRINTF_POSIX)|g' \
-e 's|@''GNULIB_VASPRINTF''@|$(GNULIB_VASPRINTF)|g' \
+ -e 's|@''GNULIB_FFLUSH''@|$(GNULIB_FFLUSH)|g' \
-e 's|@''REPLACE_FPRINTF''@|$(REPLACE_FPRINTF)|g' \
-e 's|@''REPLACE_VFPRINTF''@|$(REPLACE_VFPRINTF)|g' \
-e 's|@''REPLACE_PRINTF''@|$(REPLACE_PRINTF)|g' \
-e 's|@''REPLACE_VSPRINTF''@|$(REPLACE_VSPRINTF)|g' \
-e 's|@''HAVE_VASPRINTF''@|$(HAVE_VASPRINTF)|g' \
-e 's|@''REPLACE_VASPRINTF''@|$(REPLACE_VASPRINTF)|g' \
+ -e 's|@''REPLACE_FFLUSH''@|$(REPLACE_FFLUSH)|g' \
-e '/definition of GL_LINK_WARNING/r $(LINK_WARNING_H)' \
< $(srcdir)/stdio_.h; \
} > $@-t
--- /dev/null
+/* Test of POSIX compatible fflush() function.
+ Copyright (C) 2007 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 2, 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, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+/* Written by Eric Blake, 2007. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdio.h>
+#include <unistd.h>
+
+int
+main (int argc, char *argv[])
+{
+ FILE *f;
+ char buffer[10];
+ int fd;
+
+ /* Create test file. */
+ f = fopen ("test-fflush.txt", "w");
+ if (!f || fwrite ("1234567890", 1, 10, f) != 10 || fclose (f) != 0)
+ {
+ fputs ("Failed to create sample file.\n", stderr);
+ unlink ("test-fflush.txt");
+ return 1;
+ }
+
+ /* Test fflush. */
+ f = fopen ("test-fflush.txt", "r");
+ fd = fileno (f);
+ if (!f || 0 > fd || fread (buffer, 1, 5, f) != 5)
+ {
+ fputs ("Failed initial read of sample file.\n", stderr);
+ fclose (f);
+ unlink ("test-fflush.txt");
+ return 1;
+ }
+ /* For deterministic results, ensure f read a bigger buffer. */
+ if (lseek (fd, 0, SEEK_CUR) == 5)
+ {
+ fputs ("Sample file was not buffered.\n", stderr);
+ fclose (f);
+ unlink ("test-fflush.txt");
+ return 1;
+ }
+ /* POSIX requires fflush-fseek to set file offset of fd. */
+ if (fflush (f) != 0 || fseek (f, 0, SEEK_CUR) != 0)
+ {
+ fputs ("Failed to flush sample file.\n", stderr);
+ fclose (f);
+ unlink ("test-fflush.txt");
+ return 1;
+ }
+ /* Check that offset is correct. */
+ if (lseek (fd, 0, SEEK_CUR) != 5)
+ {
+ fputs ("File offset is wrong.\n", stderr);
+ fclose (f);
+ unlink ("test-fflush.txt");
+ return 1;
+ }
+ /* Check that file reading resumes at correct location. */
+ if (fgetc (f) != '6')
+ {
+ fputs ("Failed to read next byte of file.\n", stderr);
+ fclose (f);
+ unlink ("test-fflush.txt");
+ return 1;
+ }
+ fclose (f);
+ unlink ("test-fflush.txt");
+ return 0;
+}
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