[igraph] Hops in graph

[Surendar Swaminathan]

Hello Graph experts,

   I am trying to find number of hops between any two nodes for the
whole graph.
for example if I say

Node1    Node2

1              2
2              3
3              4

I want to say from "1" to "4" it has to pass through "2" and "3". So,
total number of hops would be 2.

Is there anyways I can do this in Igraph.

tab<- read.csv("flie.csv")
g<-graph.data.frame(tab,directed=False)
g1<-shortest.paths(g)

How do I output this in excel sheet to read them?What is the better
way to output this result ?

Help on this would be great.

Thanks
Surendar