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-rw-r--r--m4/double-slash-root.m438
1 files changed, 38 insertions, 0 deletions
diff --git a/m4/double-slash-root.m4 b/m4/double-slash-root.m4
new file mode 100644
index 0000000..c463ac4
--- /dev/null
+++ b/m4/double-slash-root.m4
@@ -0,0 +1,38 @@
+# double-slash-root.m4 serial 4 -*- Autoconf -*-
+dnl Copyright (C) 2006, 2008-2020 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_DOUBLE_SLASH_ROOT],
+[
+ AC_REQUIRE([AC_CANONICAL_HOST])
+ AC_CACHE_CHECK([whether // is distinct from /], [gl_cv_double_slash_root],
+ [ if test x"$cross_compiling" = xyes ; then
+ # When cross-compiling, there is no way to tell whether // is special
+ # short of a list of hosts. However, the only known hosts to date
+ # that have a distinct // are Apollo DomainOS (too old to port to),
+ # Cygwin, and z/OS. If anyone knows of another system for which // has
+ # special semantics and is distinct from /, please report it to
+ # <bug-gnulib@gnu.org>.
+ case $host in
+ *-cygwin | i370-ibm-openedition)
+ gl_cv_double_slash_root=yes ;;
+ *)
+ # Be optimistic and assume that / and // are the same when we
+ # don't know.
+ gl_cv_double_slash_root='unknown, assuming no' ;;
+ esac
+ else
+ set x `ls -di / // 2>/dev/null`
+ if test "$[2]" = "$[4]" && wc //dev/null >/dev/null 2>&1; then
+ gl_cv_double_slash_root=no
+ else
+ gl_cv_double_slash_root=yes
+ fi
+ fi])
+ if test "$gl_cv_double_slash_root" = yes; then
+ AC_DEFINE([DOUBLE_SLASH_IS_DISTINCT_ROOT], [1],
+ [Define to 1 if // is a file system root distinct from /.])
+ fi
+])