Golang : Search folders for file recursively with wildcard support

Ok, here is an example on how to search for a file starting from a target directory and recursively search all its sub-directories. It is pretty similar to https://www.socketloop.com/tutorials/linux-mac-os-x-search-for-files-by-filename-and-extension-with-find-command, but implemented in Golang instead of relying on combination of command line tools.

It supports wildcard search for the filename and perform simple sanity checks on the given search parameters.

Here you go!

NOTES:

If you try to execute ./findFileRecursively ./ *.go but keep getting the USAGE prompt. Escape the asterisk * first with \ or /(Windows) - ./findFileRecursively ./ \*.go

 package main

 import (
 "fmt"
 "os"
 "path/filepath"
 )

 var (
 targetFolder string
 targetFile string
 searchResult []string
 )

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

 if err != nil {
 fmt.Println(err)
 return nil
 }

 // get absolute path of the folder that we are searching
 absolute, err := filepath.Abs(path)

 if err != nil {
 fmt.Println(err)
 return nil
 }

 if fileInfo.IsDir() {
 fmt.Println("Searching directory ... ", absolute)

 // correct permission to scan folder?
 testDir, err := os.Open(absolute)

 if err != nil {
 if os.IsPermission(err) {
 fmt.Println("No permission to scan ... ", absolute)
 fmt.Println(err)
 }
 }
 testDir.Close()
 return nil
 } else {
 // ok, we are dealing with a file
 // is this the target file?

 // yes, need to support wildcard search as well
 // https://www.socketloop.com/tutorials/golang-match-strings-by-wildcard-patterns-with-filepath-match-function

 matched, err := filepath.Match(targetFile, fileInfo.Name())
 if err != nil {
 fmt.Println(err)
 }

 if matched {
 // yes, add into our search result
 add := "Found : " + absolute
 searchResult = append(searchResult, add)
 }
 }

 return nil
 }

 func main() {
 if len(os.Args) != 3 {
 fmt.Printf("USAGE : %s <target_directory> <target_file> \n", os.Args[0])
 os.Exit(0)
 }

 targetFolder = os.Args[1]
 targetFile = os.Args[2]

 fmt.Println("Searching for [", targetFile, "]")
 fmt.Println("Starting from directory [", targetFolder, "]")

 // sanity check
 testFile, err := os.Open(targetFolder)
 if err != nil {
 fmt.Println(err)
 os.Exit(-1)
 }
 defer testFile.Close()

 testFileInfo, _ := testFile.Stat()
 if !testFileInfo.IsDir() {
 fmt.Println(targetFolder, " is not a directory!")
 os.Exit(-1)
 }

 err = filepath.Walk(targetFolder, findFile)

 if err != nil {
 fmt.Println(err)
 os.Exit(-1)
 }

 // display our search result

 fmt.Println("\n\nFound ", len(searchResult), " hits!")
 fmt.Println("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@")

 for _, v := range searchResult {
 fmt.Println(v)
 }

 } 

Sample output for ./findFileRecursively ./ *main.go

Searching for [ *main.go ]

Starting from directory [ ./ ]

Searching directory ... /Users/sweetlogic

Searching directory ... /Users/sweetlogic/.Trash

Searching directory ... /Users/sweetlogic/.atom

Searching directory ... /Users/sweetlogic/.atom/.apm

Searching directory ... /Users/sweetlogic/.atom/blob-store

Searching directory ... /Users/sweetlogic/.atom/compile-cache

Searching directory ... /Users/sweetlogic/.atom/compile-cache/coffee

...

Found 103 hits!

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Found : /Users/sweetlogic/.go/src/HelloGoglandNonSingle/main.go

Found : /Users/sweetlogic/.go/src/github.com/golang/freetype/example/truetype/main.go

Found : /Users/sweetlogic/.go/src/github.com/golang/lint/testdata/blank-import-main.go

...

Happy coding!

References:

https://www.socketloop.com/tutorials/golang-match-strings-by-wildcard-patterns-with-filepath-match-function

https://www.socketloop.com/tutorials/golang-find-files-by-extension

https://golang.org/pkg/path/filepath/#WalkFunc