Go Systems Programming

A simple pattern matching example

The example of this section will improve the functionality of the countIP.go utility, by developing a program that automatically detects the field with the IP address; therefore, it will not require the user to define the field of each log entry that contains the IP address. To make things simpler, the created program will only process the first IP address of each line: findIP.go takes a single command-line argument, which is the name of the log file you want to process. The program will be presented in four parts.

The first part of findIP.go is the following:

package main 
 
import ( 
   "bufio" 
   "fmt" 
   "io" 
   "net" 
   "os" 
   "path/filepath" 
   "regexp" 
) 

The second part is where most of the magic happens with the help of ...