获取Go语言中文件的最后访问时间并计算时间差

package main

import (
    "fmt"
    "os"
    "syscall"
    "time"
)

// getAccessTime retrieves the last access time of a file.
// It works on Unix-like systems by casting os.FileInfo to syscall.Stat_t.
func getAccessTime(filePath string) (time.Time, error) {
    fileInfo, err := os.Stat(filePath)
    if err != nil {
        return time.Time{}, fmt.Errorf("failed to stat file %s: %w", filePath, err)
    }

    // Try to assert the underlying type to get access to Atim.
    // This approach is specific to Unix-like systems.
    statT, ok := fileInfo.Sys().(*syscall.Stat_t)
    if !ok {
        return time.Time{}, fmt.Errorf("cannot get access time for %s: underlying file info type is not syscall.Stat_t", filePath)
    }

    // Atim is a syscall.Timespec struct, which contains Sec and Nsec.
    accessTime := time.Unix(statT.Atim.Sec, statT.Atim.Nsec)
    return accessTime, nil
}

func main() {
    fileName := "example.txt"

    // Create a dummy file for demonstration
    file, err := os.Create(fileName)
    if err != nil {
        fmt.Printf("Error creating file: %v\n", err)
        return
    }
    file.WriteString("This is a test file.\n")
    file.Close()
    fmt.Printf("Created file: %s\n", fileName)

    // Wait a bit to ensure atime is distinct from mtime if read immediately
    time.Sleep(1 * time.Second)

    // Read the file to update its access time
    content, err := os.ReadFile(fileName)
    if err != nil {
        fmt.Printf("Error reading file: %v\n", err)
        return
    }
    fmt.Printf("Read file content: %s\n", string(content))
    time.Sleep(1 * time.Second) // Wait to ensure atime updates

    // Get the last access time
    lastAccessTime, err := getAccessTime(fileName)
    if err != nil {
        fmt.Printf("Error getting last access time: %v\n", err)
        return
    }
    fmt.Printf("Last accessed time of %s: %s\n", fileName, lastAccessTime.Format(time.RFC3339))

    // Get the current time
    currentTime := time.Now()
    fmt.Printf("Current time: %s\n", currentTime.Format(time.RFC3339))

    // Calculate the duration since last access
    duration := currentTime.Sub(lastAccessTime)
    fmt.Printf("Time since last access: %s\n", duration)

    // Clean up the dummy file
    os.Remove(fileName)
}

// lastAccessTime is the time.Time object obtained from getAccessTime
// currentTime is time.Now()

duration := currentTime.Sub(lastAccessTime)
fmt.Printf("Time since last access: %s\n", duration)