Checks and returns true/false if there's any closed file (i.e not open file) in the given directory. anyclosedfile.In('/abs/path/to/dir')

anyclosedfile.go

package anyclosedfile

import (
	"log"
	"os"
	"os/exec"
	"path/filepath"
)

// In checks the given directory for files that are not being actively written to
// It return true if any file is found and return false otherwise
// It return any error that occurs
func In(dir string) (bool, error) {
	// Initalize the verdict to false
	foundClosedFile := false
	// filepath.Walk iteratively executes the given function for each file in the specified directory
	// and returns an error if something goes wrong
	err := filepath.Walk(dir, func(path string, file os.FileInfo, er error) error {
		// if an error occurs for the given file
		if er != nil {
			return er // return the error
		}

		// the walk function nicely recurses into subdirectory as well
		// so we check that the current file in focus is not a directory
		// and then check that it's not closed using the 'lsof' shell command
		if !file.IsDir() && exec.Command("lsof", path).Run() != nil {
			// in here means
			// 1. file is not a directory
			// 2. file is not open by any known process
			log.Printf("Error: file -> %s is completed\n", file.Name()) // log the file
			foundClosedFile = true                                      // update the initial verdict
		}
		return nil // return nil since we didn't encounter any error
	})

	return foundClosedFile, err // return the verdict and err (if any)
}