Shell Programming and Scripting

1.1.1.1   2.2.2.2         TCP                       22
1.1.1.1   2.2.2.2         TCP                       31
1.1.1.1   2.2.2.2         TCP                       45
1.1.1.1   2.2.2.2         TCP                       67
1.1.1.3   2.2.2.2         TCP                       22
1.1.1.3   2.2.2.2         TCP                       89
1.1.1.3   2.2.2.2         TCP                       78
1.1.1.1   2.2.2.3         TCP                       78
1.1.1.1   2.2.2.3         TCP                       79

1.1.1.1   2.2.2.2         TCP                       22, 31, 45, 67
1.1.1.3   2.2.2.2         TCP                       22, 89, 78
1.1.1.1   2.2.2.3         TCP                       78, 79

awk '
  # idx is an index constructed by concatenating first 3 fields in the line
  {idx=$1 FS $2 FS $3} 

  # a - an array indexed by 'idx'.
  # if idx is in a, add forth field to it; if not, assign forth field as the first entry in array a
  {a[idx]=(idx in a)?a[idx] OFS $4:$4} 

  # after all records/lines have been process...
  # iterate through all the indecies in array a, print out the value of the index and
  # the corresponding value stored in the array with the current index.
  END {for(i in a) print i FS a[i]}' OFS=, myInputFileGoesHere