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-rw-r--r--gnulib-m4/dup2.m435
1 files changed, 35 insertions, 0 deletions
diff --git a/gnulib-m4/dup2.m4 b/gnulib-m4/dup2.m4
new file mode 100644
index 00000000..2abc74cd
--- /dev/null
+++ b/gnulib-m4/dup2.m4
@@ -0,0 +1,35 @@
+#serial 6
+dnl Copyright (C) 2002, 2005, 2007, 2009 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_DUP2],
+[
+ AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+ AC_REQUIRE([AC_CANONICAL_HOST])
+ AC_CHECK_FUNCS_ONCE([dup2])
+ if test $ac_cv_func_dup2 = no; then
+ HAVE_DUP2=0
+ AC_LIBOBJ([dup2])
+ else
+ AC_CACHE_CHECK([whether dup2 works], [gl_cv_func_dup2_works],
+ [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <unistd.h>
+]], [return 1 - dup2 (1, 1);])],
+ [gl_cv_func_dup2_works=yes], [gl_cv_func_dup2_works=no],
+ [case "$host_os" in
+ mingw*) # on this platform, dup2 always returns 0 for success
+ gl_cv_func_dup2_works=no;;
+ cygwin*) # on cygwin 1.5.x, dup2(1,1) returns 0
+ gl_cv_func_dup2_works=no;;
+ *) gl_cv_func_dup2_works=yes;;
+ esac])])
+ if test "$gl_cv_func_dup2_works" = no; then
+ REPLACE_DUP2=1
+ AC_LIBOBJ([dup2])
+ fi
+ fi
+ AC_DEFINE_UNQUOTED([REPLACE_DUP2], [$REPLACE_DUP2],
+ [Define to 1 if dup2 returns 0 instead of the target fd.])
+])