blob: 31ee2621e400715208d11da690ca33e42badebba [file] [log] [blame]
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package os
import (
"internal/poll"
"io"
"syscall"
"unsafe"
)
// FIXME: pathconf returns long, not int.
//extern pathconf
func libc_pathconf(*byte, int32) int
func direntType(*syscall.Dirent) byte
func clen(n []byte) int {
for i := 0; i < len(n); i++ {
if n[i] == 0 {
return i
}
}
return len(n)
}
func (f *File) readdir(n int, mode readdirMode) (names []string, dirents []DirEntry, infos []FileInfo, err error) {
// If this file has no dirinfo, create one.
if f.dirinfo == nil {
fd, call, err := poll.DupCloseOnExec(int(f.pfd.Sysfd))
if err != nil {
return nil, nil, nil, NewSyscallError(call, err)
}
syscall.Entersyscall()
r := libc_fdopendir(int32(fd))
errno := syscall.GetErrno()
syscall.Exitsyscall()
if r == nil {
return nil, nil, nil, &PathError{"fdopendir", f.name, errno}
}
f.dirinfo = &dirInfo{r}
}
dir := f.dirinfo.dir
// Change the meaning of n for the implementation below.
//
// The n above was for the public interface of "if n <= 0,
// Readdir returns all the FileInfo from the directory in a
// single slice".
//
// But below, we use only negative to mean looping until the
// end and positive to mean bounded, with positive
// terminating at 0.
if n == 0 {
n = -1
}
for n != 0 {
syscall.Entersyscall()
syscall.SetErrno(0)
dirent := libc_readdir(dir)
errno := syscall.GetErrno()
syscall.Exitsyscall()
if dirent == nil {
if errno != 0 {
return names, dirents, infos, &PathError{Op: "readdir", Path: f.name, Err: errno}
}
break // EOF
}
// In some cases the actual name can be longer than
// the Name field.
name := (*[1 << 16]byte)(unsafe.Pointer(&dirent.Name[0]))[:]
for i, c := range name {
if c == 0 {
name = name[:i]
break
}
}
// Check for useless names before allocating a string.
if (len(name) == 1 && name[0] == '.') || (len(name) == 2 && name[0] == '.' && name[1] == '.') {
continue
}
if n > 0 { // see 'n == 0' comment above
n--
}
if mode == readdirName {
names = append(names, string(name))
} else if mode == readdirDirEntry {
var typ FileMode
switch direntType(dirent) {
case 'B':
typ = ModeDevice
case 'C':
typ = ModeDevice | ModeCharDevice
case 'D':
typ = ModeDir
case 'F':
typ = ModeNamedPipe
case 'L':
typ = ModeSymlink
case 'R':
typ = 0
case 'S':
typ = ModeSocket
case 'U':
typ = ^FileMode(0)
}
de, err := newUnixDirent(f.name, string(name), typ)
if IsNotExist(err) {
// File disappeared between readdir and stat.
// Treat as if it didn't exist.
continue
}
if err != nil {
return nil, dirents, nil, err
}
dirents = append(dirents, de)
} else {
info, err := lstat(f.name + "/" + string(name))
if IsNotExist(err) {
// File disappeared between readdir + stat.
// Treat as if it didn't exist.
continue
}
if err != nil {
return nil, nil, infos, err
}
infos = append(infos, info)
}
}
if n > 0 && len(names)+len(dirents)+len(infos) == 0 {
return nil, nil, nil, io.EOF
}
return names, dirents, infos, nil
}