How to only add unique elements to an array in awk from sevral input text files

as the toppic suggests, how to I read in information from multiple text files and only add elements 1 time in a an array regardless if they occur multiple times in the diffrent text files?

I have started with this script that reads in and prints out all elements in the order that they occur in the different documents.

For example take e look at these 3 diffrent text files containing the following data

File 1:

2011-01-22 22:12 test1 22 1312 75 13.55 1399 
2011-01-23 22:13 test4 22 1112 72 12.55 1499

File 2:

2011-01-24 22:14 test1 21 1322 75 23.55 1599 
2011-01-25 22:15 test2 23 2312 77 33.55 1699 

File 3:

2011-01-26 22:16 test2 20 1412 79 63.55 1799 
2011-01-27 22:17 test5 12 1352 78 43.55 1999 

I want to check if the current element already is added to the array, but as for now my script prints out all elements.

{
    BUILDd[NR-1] = $3; len++
}
   END { 
        SUBSYSTEM=substr(FILENAME, 1, length(FILENAME)-7)
        LABEL= "\"" toupper(SUBSYSTEM) "\""
        print  "#{"
        print "\"buildnames\": {"
        print "        \"label\": \"buildnames\","
        print "        \"data\": ["
        for (i = 0 ; i <= len-1; i ++ ) {
        if(i == len-1){print "            [\"" BUILDd[i] "\"]"}
        else
            { print "            [\"" BUILDd[i] "\"],"}
        }
        print "        ]"
        print " }"
        print "};"
}

Gives this output

#{
"buildnames": {
        "label": "buildnames开发者_Go百科",
        "data": [
            ["test1"]
            ["test4"]
            ["test1"]
            ["test2"]
            ["test2"]
            ["test5"]
        ]
        }
};

When I want it to give out the following

#{
"buildnames": {
        "label": "buildnames",
        "data": [
            ["test1"]
            ["test2"]
            ["test4"]
            ["test5"]
        ]
        }
};

1) In other words first check if the elements are already in the array and if not, then add it/them

2) Sort the array afterwards if possible

Thanks =)

Except for the formatting, is this what you are trying to achieve (a, b, c, are files that contains your logs) ?

$ cut -d" " -f3 a b c | sort | uniq
test1
test2
test4
test5

using awk

{
    BUILDd[$3] = 1
}
END {
    for (i in BUILDd) {
    print i
    }
}

Gives

awk -f a.awk a b c
test1
test2
test4
test5

Note that the correct sorting order here is pure accidental... The order stuff is put into a array is not the order it is printed.