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LDP/guide/docbook/abs-guide/embedded-arrays.sh

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+#!/bin/bash
+# embedded-arrays.sh
+# Embedded arrays and indirect references.
+
+# This script by Dennis Leeuw.
+# Used with permission.
+# Modified by document author.
+
+
+ARRAY1=(
+        VAR1_1=value11
+        VAR1_2=value12
+        VAR1_3=value13
+)
+
+ARRAY2=(
+        VARIABLE="test"
+        STRING="VAR1=value1 VAR2=value2 VAR3=value3"
+        ARRAY21=${ARRAY1[*]}
+)       # Embed ARRAY1 within this second array.
+
+function print () {
+        OLD_IFS="$IFS"
+        IFS=$'\n'       #  To print each array element
+                        #+ on a separate line.
+        TEST1="ARRAY2[*]"
+        local ${!TEST1} # See what happens if you delete this line.
+        #  Indirect reference.
+	#  This makes the components of $TEST1
+	#+ accessible to this function.
+
+
+        #  Let's see what we've got so far.
+        echo
+        echo "\$TEST1 = $TEST1"       #  Just the name of the variable.
+        echo; echo
+        echo "{\$TEST1} = ${!TEST1}"  #  Contents of the variable.
+                                      #  That's what an indirect
+                                      #+ reference does.
+        echo
+        echo "-------------------------------------------"; echo
+        echo
+
+
+        # Print variable
+        echo "Variable VARIABLE: $VARIABLE"
+	
+        # Print a string element
+        IFS="$OLD_IFS"
+        TEST2="STRING[*]"
+        local ${!TEST2}      # Indirect reference (as above).
+        echo "String element VAR2: $VAR2 from STRING"
+
+        # Print an array element
+        TEST2="ARRAY21[*]"
+        local ${!TEST2}      # Indirect reference (as above).
+        echo "Array element VAR1_1: $VAR1_1 from ARRAY21"
+}
+
+print
+echo
+
+exit 0
+
+#   As the author of the script notes,
+#+ "you can easily expand it to create named-hashes in bash."
+#   (Difficult) exercise for the reader: implement this.