CHAPTER 6: LOGGING OPTIONS
Nmap provides numerous methods of logging the scan output. Nmap's output logs not only save important scan information, they also provide a method of restarting a previously cancelled scan.
In all of the output formats, the filename can be replaced with a hypen (-) to redirect the output to stdout. This can be useful if the output information will be used by another piped process on the same command line.
Normal Format (-oN <logfilename>)
Nmap's normal output format (-oN) saves a similar view of the output that's displayed on the screen during an nmap scan. This readable text is useful when the output is used in a document or printed for later reference.
This saved information is very similar to the run-time output, except for some additional initialization information at the top of the scan:
# nmap 3.81 scan initiated Fri May 20 21:00:50 2005 as: ./nmap -v -sS -oA oA9 192.168.0.9 Interesting ports on 192.168.0.9: (The 1654 ports scanned but not shown below are in state: closed) PORT STATE SERVICE 21/tcp open ftp 22/tcp open ssh 23/tcp open telnet 79/tcp open finger 110/tcp open pop3 111/tcp open rpcbind 514/tcp open shell 886/tcp open unknown 2049/tcp open nfs MAC Address: 00:03:47:6D:28:D7 (Intel) # Nmap run completed at Fri May 20 21:01:01 2005 -- 1 IP address (1 host up) scanned in 10.950 secondsThis output type doesn't follow any particular format. All of the nmap information is jumbled together onto separate lines of output, with a text layout that differs slightly for every scan. This variability makes it difficult for other tools to process the information contained in the output file.
Most of the examples in this book are taken from a normal format output file!

