Shell Programming and Scripting

File 1
------
List 1
     Object 1
     Object 2
List 2
     Object 3 
     Object 1
List 3
     Object 2
     Object 5

File2
-----
Object 1
Object 3
Object 4

List 1 has 1 objects from File2
List 2 has 2 objects from File2
List 3 has 0 objects from File2

awk ' BEGIN {
        F = "file1"
        while ( (getline line < F) > 0 )
        {
                gsub(/^[ \t]*|[ \t]*$/, x, line)
                if ( line ~ /List/ )
                        L = line
                if ( line !~ /List/ )
                        A[L] = ( A[L] == "" ? line : A[L] "," line )
        }
        close (F)

        F = "file2"
        while ( (getline line < F) > 0 )
        {
                gsub(/^[ \t]*|[ \t]*$/, x, line)
                for ( k in A )
                {
                        n = split ( A[k], R, ",")
                        for ( j = 1; j <=n; j++ )
                        {
                                if ( line == R[j] )
                                        C[k]++
                        }
                }
        }
        close(F)

        for ( k in A )
                print k " has " (C[k] == "" ? 0 : C[k]) " objects from file2"
} '

awk '
NR==FNR {obj[$1$2]=1; fn=FILENAME; next}
/^List/ {
if(s!="") printf "%s has %d objects from %s\n",s,cnt,fn
s=$0; cnt=0
next
}
$1$2 in obj {cnt++}
END {
if(s!="") printf "%s has %d objects from %s\n",s,cnt,fn
}' File2 File1