| 1 | # double-slash-root.m4 serial 4   -*- Autoconf -*-
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| 2 | dnl Copyright (C) 2006, 2008-2022 Free Software Foundation, Inc.
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| 3 | dnl This file is free software; the Free Software Foundation
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| 4 | dnl gives unlimited permission to copy and/or distribute it,
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| 5 | dnl with or without modifications, as long as this notice is preserved.
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| 6 | 
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| 7 | AC_DEFUN([gl_DOUBLE_SLASH_ROOT],
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| 8 | [
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| 9 |   AC_REQUIRE([AC_CANONICAL_HOST])
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| 10 |   AC_CACHE_CHECK([whether // is distinct from /], [gl_cv_double_slash_root],
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| 11 |     [ if test x"$cross_compiling" = xyes ; then
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| 12 |         # When cross-compiling, there is no way to tell whether // is special
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| 13 |         # short of a list of hosts.  However, the only known hosts to date
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| 14 |         # that have a distinct // are Apollo DomainOS (too old to port to),
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| 15 |         # Cygwin, and z/OS.  If anyone knows of another system for which // has
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| 16 |         # special semantics and is distinct from /, please report it to
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| 17 |         # <bug-gnulib@gnu.org>.
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| 18 |         case $host in
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| 19 |           *-cygwin | i370-ibm-openedition)
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| 20 |             gl_cv_double_slash_root=yes ;;
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| 21 |           *)
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| 22 |             # Be optimistic and assume that / and // are the same when we
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| 23 |             # don't know.
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| 24 |             gl_cv_double_slash_root='unknown, assuming no' ;;
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| 25 |         esac
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| 26 |       else
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| 27 |         set x `ls -di / // 2>/dev/null`
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| 28 |         if test "$[2]" = "$[4]" && wc //dev/null >/dev/null 2>&1; then
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| 29 |           gl_cv_double_slash_root=no
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| 30 |         else
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| 31 |           gl_cv_double_slash_root=yes
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| 32 |         fi
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| 33 |       fi])
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| 34 |   if test "$gl_cv_double_slash_root" = yes; then
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| 35 |     AC_DEFINE([DOUBLE_SLASH_IS_DISTINCT_ROOT], [1],
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| 36 |       [Define to 1 if // is a file system root distinct from /.])
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| 37 |   fi
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| 38 | ])
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