1set/gut

package yos

import (
    "os"
    "path/filepath"
)

// GetFileSize returns the size in bytes for a regular file.
//
// If the given path is a symbolic link, it will be followed.
func GetFileSize(path string) (size int64, err error) {
    var fi os.FileInfo
    if fi, err = os.Stat(path); err == nil {
        if isFileFi(&fi) {
            size = fi.Size()
        } else {
            err = opError(opnSize, path, errNotRegularFile)
        }
    }
    return
}

// GetSymlinkSize returns the size in bytes for a symbolic link.
func GetSymlinkSize(path string) (size int64, err error) {
    var fi os.FileInfo
    if fi, err = os.Lstat(path); err == nil {
        if isSymlinkFi(&fi) {
            size = fi.Size()
        } else {
            err = opError(opnSize, path, errNotSymlink)
        }
    }
    return
}

// GetDirSize returns total size in bytes for all regular files and symbolic links in a directory.
//
// If the given path is a symbolic link, it will be followed, but symbolic links inside the directory won't.
func GetDirSize(path string) (size int64, err error) {
    var (
        rootFi os.FileInfo
        root   string
    )
    if root, rootFi, err = resolveDirInfo(path); err == nil {
        err = filepath.Walk(root, func(itemPath string, itemFi os.FileInfo, errIn error) (errOut error) {
            errOut = errIn
            if os.SameFile(rootFi, itemFi) || errOut != nil {
                return
            }
            if isFileFi(&itemFi) || isSymlinkFi(&itemFi) {
                size += itemFi.Size()
            }
            return
        })
    } else {
        err = opError(opnSize, path, err)
    }
    return
}