Finding files in a directory using go - absolute filepath

main.go

package main

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

var (
	fileExtension = ".properties"
	searchPath    = "../"
	files         []string
)

func main() {
	fmt.Println(checkExt(fileExtension, searchPath))
}

func checkExt(ext, pathforsearching string) []string {
	pathS := searchPath

	filepath.Walk(pathS, func(path string, f os.FileInfo, _ error) error {
		if !f.IsDir() {
			r, err := regexp.MatchString(ext, f.Name())
			if err == nil && r {
				absolutefilepath, err := filepath.Abs(path)
				if err != nil {
					log.Fatal(err)
				}
				files = append(files, absolutefilepath)
			}
		}
		return nil
	})
	return files
}

// This returns the absolute filepath to each file - use this one instead if you just want the filenames: https://gist.github.com/aln787/ea40d18cc33c7a983549

package main

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

var (
	filepattern = "dir1"
	searchPath  = "./searchfolder"
	searchtype  = "folder" // change to 'file' for just files or 'all' for both files and folders
)

func main() {

	fmt.Println(search(filepattern, searchPath, searchtype))
}

func search(pattern, pathforsearching, filetype string) []string {

	var files []string

	if filetype == "all" {
		filepath.Walk(pathforsearching, func(path string, f os.FileInfo, _ error) error {
			r, err := regexp.MatchString(pattern, f.Name())
			if err == nil && r {
				absolutefilepath, err := filepath.Abs(path)
				if err != nil {
					log.Fatal(err)
				}
				files = append(files, absolutefilepath)
			}
			return nil
		})
	}

	if filetype == "file" {
		filepath.Walk(pathforsearching, func(path string, f os.FileInfo, _ error) error {
			if !f.IsDir() {
				r, err := regexp.MatchString(pattern, f.Name())
				if err == nil && r {
					absolutefilepath, err := filepath.Abs(path)
					if err != nil {
						log.Fatal(err)
					}
					files = append(files, absolutefilepath)
				}
			}
			return nil
		})
	}

	if filetype == "folder" {
		filepath.Walk(pathforsearching, func(path string, f os.FileInfo, _ error) error {
			if f.IsDir() {
				r, err := regexp.MatchString(pattern, f.Name())
				if err == nil && r {
					absolutefilepath, err := filepath.Abs(path)
					if err != nil {
						log.Fatal(err)
					}
					files = append(files, absolutefilepath)
				}
			}
			return nil
		})
	}

	return files
}

Or using a method:

package main

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

func main() {
	myfirstfile := Filesearch{Pattern: "properties", Path: "./", Filetype: "all"}
	filearray := myfirstfile.Searchv2()
	fmt.Println(filearray)

}

// Filesearch - type for instantiating a search method
type Filesearch struct {
	Pattern  string
	Path     string
	Filetype string
}

// Searchv2 - this is a function for searching a directory for a file/folder/both using the filesearch type
func (file *Filesearch) Searchv2() []string {

	var files []string
	pattern := file.Pattern
	pathforsearching := file.Path
	filetype := file.Filetype

	if filetype == "all" {
		filepath.Walk(pathforsearching, func(path string, f os.FileInfo, _ error) error {
			// if !f.IsDir() {
			r, err := regexp.MatchString(pattern, f.Name())
			if err == nil && r {
				absolutefilepath, err := filepath.Abs(path)
				if err != nil {
					log.Fatal(err)
				}
				files = append(files, absolutefilepath)
				// }
			}
			return nil
		})
	}

	if filetype == "file" {
		filepath.Walk(pathforsearching, func(path string, f os.FileInfo, _ error) error {
			if !f.IsDir() {
				r, err := regexp.MatchString(pattern, f.Name())
				if err == nil && r {
					absolutefilepath, err := filepath.Abs(path)
					if err != nil {
						log.Fatal(err)
					}
					files = append(files, absolutefilepath)
				}
			}
			return nil
		})
	}

	if filetype == "folder" {
		filepath.Walk(pathforsearching, func(path string, f os.FileInfo, _ error) error {
			if f.IsDir() {
				r, err := regexp.MatchString(pattern, f.Name())
				if err == nil && r {
					absolutefilepath, err := filepath.Abs(path)
					if err != nil {
						log.Fatal(err)
					}
					files = append(files, absolutefilepath)
				}
			}
			return nil
		})
	}

	return files
}