On Wed, Nov 17, 2010 at 08:19:53PM +0200, arturs.onz...@gmail.com wrote:
Hi all. It will be great if some one will help me to solve my home task. So,
the deal : i have .pcap file, i convert it to csv using tcpdump (tcpdump -tt
-n -r x.pcap x.csv)
CSV file looks like that :
12890084,761659 IP 10.10.20.20.47808 10.10.20.255.47808: UDP, length 12
12890084,761659 IP 10.10.20.20.47808 10.10.20.255.47808: TCP, length 12
12890084,761659 IP 10.10.20.20.47808 10.10.20.255.47808: HTML, length 12
...
10 rows.
Now, i need to open csv in R, and solve 5 problems, but i need to work only
with UDP packets (not TCP,HTMP...). For example i need to count how many
UDP packets are there, max and min time in UDP and so on. I see only two
answers.. i need to scan (but how?) for UDP or i need to separate this
csv, cut only needed rows, and work with them. Please help.
You can read the file into R and extract only UDP rows for example
all - read.csv(x.csv, stringsAsFactors=FALSE, header=FALSE) # assuming
there is no header
udp - all[grep( UDP$, all[, 2]), ]
Using concatenation of three copies of your 3 rows, we get
all
V1 V2 V3
1 12890084 761659 IP 10.10.20.20.47808 10.10.20.255.47808: UDP length 12
2 12890084 761659 IP 10.10.20.20.47808 10.10.20.255.47808: TCP length 12
3 12890084 761659 IP 10.10.20.20.47808 10.10.20.255.47808: HTML length 12
4 12890084 761659 IP 10.10.20.20.47808 10.10.20.255.47808: UDP length 12
5 12890084 761659 IP 10.10.20.20.47808 10.10.20.255.47808: TCP length 12
6 12890084 761659 IP 10.10.20.20.47808 10.10.20.255.47808: HTML length 12
7 12890084 761659 IP 10.10.20.20.47808 10.10.20.255.47808: UDP length 12
8 12890084 761659 IP 10.10.20.20.47808 10.10.20.255.47808: TCP length 12
9 12890084 761659 IP 10.10.20.20.47808 10.10.20.255.47808: HTML length 12
udp
V1V2 V3
1 12890084 761659 IP 10.10.20.20.47808 10.10.20.255.47808: UDP length 12
4 12890084 761659 IP 10.10.20.20.47808 10.10.20.255.47808: UDP length 12
7 12890084 761659 IP 10.10.20.20.47808 10.10.20.255.47808: UDP length 12
Note that there are three columns only, since your input had only three fields
per line. If you change the export to .csv so that, for example, column 2
contains
only the protocol name, you could use
table(all[, 2])
to get the number of occurrences of each protocol or
sum(all[, 2] == UDP)
to get the number of UDP rows or
udp - all[all[, 2] == UDP, ]
to extract only UDP rows.
If you cannot change the export to .csv, you can use the function strsplit().
Petr Savicky.
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