CONFIG: verify bash version for completion support

- the (global) associative array requires bash >= 4.2

etc/bashrc

@@ -175,7 +175,7 @@ then
     _foamEtc config.sh/aliases
 
     # Bash completions
-    if command -v complete > /dev/null 2>&1
+    if [ "${BASH_VERSINFO:-0}" -ge 4 ]
     then
         _foamEtc config.sh/bash_completion
     fi

etc/config.csh/complete-wrapper

@@ -25,6 +25,15 @@
 #------------------------------------------------------------------------------
 [ "$#" -ge 1 ] || exit 1
 
+# Support '-test' option to check bash version
+if [ "$1" = "-test" ]
+then
+    # Uses 'declare -gA' for the implementation
+    # The '-A' requires bash >= 4.0 and the '-g' requires bash >= 4.2
+    [ "${BASH_VERSINFO[0]:-0}${BASH_VERSINFO[1]:-0}" -ge 42 ]
+    exit $?
+fi
+
 # Preload completion cache
 if [ -f $WM_PROJECT_DIR/etc/config.sh/completion_cache ]
 then  . $WM_PROJECT_DIR/etc/config.sh/completion_cache

etc/config.csh/tcsh_completion

 #----------------------------------*-sh-*--------------------------------------
-# Tcsh completions for OpenFOAM applications
-# Using bash_completion functions for the hard work
+# =========                 |
+# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+#  \\    /   O peration     |
+#   \\  /    A nd           | Copyright (C) 2017 OpenCFD Ltd.
+#    \\/     M anipulation  |
+#------------------------------------------------------------------------------
+# This file is part of OpenFOAM, licensed under the GNU General Public License
+# <http://www.gnu.org/licenses/>.
+#
+# File
+#     etc/config.csh/tcsh_completion
+#
+# Description
+#     Tcsh completions for OpenFOAM applications
+#     Using bash completion for the hard work
+#
+# Requires
+#     bash 4.2 or newer
+#
+#------------------------------------------------------------------------------
 
 if ($?tcsh) then  # tcsh only
 
     # Remove old completions, which look like:
     #   complete APPNAME 'p,*,`bash $WM_PROJECT_DIR/etc/ ...
     foreach appName (`complete | sed -ne '/WM_PROJECT/s/\t.*$//p'`)
-        uncomplete $cleaned
+        uncomplete $appName
     end
 
-    # Generate completions for predefined directories
-    foreach dirName ("$FOAM_APPBIN")
-        if ( ! -d $dirName || ! -f $WM_PROJECT_DIR/etc/config.csh/complete-wrapper ) continue
-        foreach appName (`find $dirName -maxdepth 1 -executable -type f`)
-            # Pass explicitly
-            ## complete $appName:t 'p,*,`bash $WM_PROJECT_DIR/etc/config.csh/complete-wrapper '$appName:t' "${COMMAND_LINE}"`,'
-            # Pass via environment
-            complete $appName:t 'p,*,`bash $WM_PROJECT_DIR/etc/config.csh/complete-wrapper '$appName:t'`,'
+    # Generate completions for predefined directories (if support is possible)
+    bash $WM_PROJECT_DIR/etc/config.csh/complete-wrapper -test
+    if ($status == 0) then
+        foreach dirName ("$FOAM_APPBIN")
+            if ( ! -d $dirName ) continue
+            foreach appName (`find $dirName -maxdepth 1 -executable -type f`)
+                # Pass explicitly
+                ## complete $appName:t 'p,*,`bash $WM_PROJECT_DIR/etc/config.csh/complete-wrapper '$appName:t' "${COMMAND_LINE}"`,'
+                # Pass via environment
+                complete $appName:t 'p,*,`bash $WM_PROJECT_DIR/etc/config.csh/complete-wrapper '$appName:t'`,'
+            end
         end
-    end
+    endif
+
 endif
 
 #------------------------------------------------------------------------------

etc/config.sh/bash_completion

@@ -22,8 +22,24 @@
 # Uses
 #     _of_complete_cache_
 #
+# Requires
+#     bash 4.2 or newer
+#
 #------------------------------------------------------------------------------
 
+# Remove old completions (skip for tcsh wrapper), which look like:
+#     "complete ... -F _of_complete_ APPNAME
+if [ -z "$_of_complete_tcsh" ]
+then
+    # For economy, obtain list first
+    foamOldDirs="$(complete 2>/dev/null | sed -ne 's/^.*-F _of_.* \(..*\)$/\1/p')"
+    for cleaned in $foamOldDirs
+    do
+        complete -r $cleaned 2>/dev/null
+    done
+fi
+
+
 # Add completion for command or directory of commands
 # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 unset -f foamAddCompletion 2>/dev/null
@@ -173,26 +189,34 @@ _of_complete_()
 
 #------------------------------------------------------------------------------
 
-# Global associative array (cached options for OpenFOAM applications)
-declare -gA _of_complete_cache_;
 
-# Clear existing cache and reassign bash completions.
-# But for tcsh wrapper make use of caching and avoid this overhead.
-if [ -z "$_of_complete_tcsh" ]
+# Uses 'declare -gA' for the implementation
+# The '-A' requires bash >= 4.0 and the '-g' requires bash >= 4.2
+if [ "${BASH_VERSINFO[0]:-0}${BASH_VERSINFO[1]:-0}" -ge 42 ]
 then
-    _of_complete_cache_=()
-
-    # Remove old completions, which look like:
-    #     "complete ... -F _of_complete_ APPNAME
-    # For economy, obtain list first
-    foamOldDirs="$(complete 2>/dev/null | sed -ne 's/^.*-F _of_.* \(..*\)$/\1/p')"
-    for cleaned in $foamOldDirs
-    do
-        complete -r $cleaned 2>/dev/null
-    done
-
-    # Generate completions for predefined directories
-    foamAddCompletion $FOAM_APPBIN
+    # Global associative array (cached options for OpenFOAM applications)
+    declare -gA _of_complete_cache_;
+
+    # Clear existing cache and reassign bash completions.
+    # But for tcsh wrapper make use of caching and avoid this overhead.
+    if [ -z "$_of_complete_tcsh" ]
+    then
+        _of_complete_cache_=()
+
+        # Generate completions for predefined directories
+        foamAddCompletion $FOAM_APPBIN
+    fi
+else
+    # Bash version is too old.
+    ## echo "No bash completions - requires bash >= 4.2" 1>&2
+
+    unset -f foamAddCompletion 2>/dev/null
+    foamAddCompletion()
+    {
+        echo "foamAddCompletion disabled - requires bash >= 4.2" 1>&2
+    }
+
+    unset -f _of_complete_ 2>/dev/null
 fi
 
 #------------------------------------------------------------------------------