Search includes of the includes for includes and errorcodes

#!/bin/bash

function search-includes()
{
    IFS=$'\n'
    SEARCH="$1"
    if test -n "$2";
    then
        if test "$2" == "DEBUG"
        then
            DEBUG="TRUE"
        else
            SEARCHED="$2";
        fi
    fi

    if test -n "$3";
    then
        TABS="$3"
    fi

    if test -n "$4";
    then
        DEBUG="TRUE"
    fi

    if test $DEBUG == "TRUE";
    then
        echo -e $TABS"Searching file $SEARCH for includes"
    fi

    if test -n "$SEARCH";
    then
        grep -iE "#[ ]{0,}include" "$SEARCH"
        BASESEARCH=`basename $SEARCH`;
        for d in `grep -iE "#[ ]{0,}include" "$SEARCH" | \
            grep -v "$BASESEARCH" | \
            grep -Po "(\<|\"){1}.*\.h(\>|\"){1}" | \
            cut -c2- | rev | cut -c2- | rev | \
            sort | uniq`;
        do
            LOCATION=`slocate $d | grep "^\/usr\/include\/" | head -n1`;
            if test $DEBUG == "TRUE";
            then
                echo -e $TABS"Search file $LOCATION for error codes";
            fi

            grep -Pi "^#[]{0,}define( |\t){1,}E{1}[A-Za-z0-9]*[0-9]{1,3}" "$LOCATION";

            if test $DEBUG == "TRUE";
            then
                echo -e $TABS"Testing if $LOCATION has previously been searched, previous searches were $SEARCHED";
            fi

            if test -z $SEARCHED || test -n `echo "$LOCATION" | grep -viE "($(exec echo $SEARCHED))"`;
            then
                if test $DEBUG == "TRUE";
                then
                    echo -e $TABS"Searching sub includes"
                fi

                TABS="$TABS\t"
                if test -z $SEARCHED;
                then
                    SEARCHED="$LOCATION"
                else
                    SEARCHED="$SEARCHED|$LOCATION"
                fi
                search-includes "$LOCATION" "$SEARCHED" "$TABS" "DEBUG"
            fi
        done
    fi
}