Shell Programming and Scripting

ITEM1	AAAAA	1
ITEM1	BBBBB	1
ITEM1	CCCCC	1
ITEM2	AAAAA	5
ITEM2	CCCCC	4

ITEM1	AAAAA	1
		BBBBB	1
		CCCCC	1
ITEM1	TOTAL	3

ITEM2	AAAAA	5
		CCCCC	4
TTEM2	TOTAL	9

		TOTAL	12

awk '
  function pr(i) {
    printf "%s", i A[i]
    print  i, "TOTAL", T[i]
  }
  {
    if(i!=$1 && NR>1) pr(i)
    i=$1
    $1=x
    A[i]=A[i] $0 ORS
    T[i]+=$3
    GT+=$3
  }
  END {
    pr(i)
    print "", "TOTAL", GT}
' OFS='\t' file

awk '
  {
    i=$1;
    $1=x
    A[i]=A[i] $0 ORS
    T[i]+=$3
    GT+=$3
  } 
  END {
    for(i in A) {
      printf "%s",i A[i]
      print  i, "TOTAL", T[i]
    }
    print "", "TOTAL", GT
  }
' OFS='\t' file