Examples of regular expression search capabilities in go language files

This article illustrates the regular expression search for go language files as an example. I will share it with you for your reference as follows:

package main

import (

    "fmt"

    "os"

    "path/filepath"

    "regexp"

)

func main() {

    //  Command line argument 

    args := os.Args

    //  Check the parameters 

    if len(args) == 1 {

        fmt.Println("ff is a file find tool. use like bottom")

        fmt.Println("ff [dir] [regexp]")

        return

    }

    if len(args) < 3 {

        fmt.Println("args < 3")

        return

    }

    fileName := args[1]

    pattern := args[2]

    file, err := os.Open(fileName)

    if err != nil {

        fmt.Println(err)

        return

    }

    fi, err := file.Stat()

    if err != nil {

        fmt.Println(err)

        return

    }

    if !fi.IsDir() {

        fmt.Println(fileName, " is not a dir")

    }

    reg, err := regexp.Compile(pattern)

    if err != nil {

        fmt.Println(err)

        return

    }

    //  Directory traversal 

    filepath.Walk(fileName,

        func(path string, f os.FileInfo, err error) error {

            if err != nil {

                fmt.Println(err)

                return err

            }

            if f.IsDir() {

                return nil

            }

            //  Match the directory 

            matched := reg.MatchString(f.Name())

            if matched {

                fmt.Println(path)

            }

            return nil

        })

}

PS: here are two more handy regular expression tools for you to use:

JavaScript regular expression online testing tool:
http://tools.ofstack.com/regex/javascript

Online regular expression generation tool:
http://tools.ofstack.com/regex/create_reg

I hope this article has been helpful to you in the programming of Go language.