103 lines
2.1 KiB
Go
103 lines
2.1 KiB
Go
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package os
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import (
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"io"
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"sync/atomic"
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"syscall"
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"unsafe"
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)
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//extern opendir
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func libc_opendir(*byte) *syscall.DIR
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//extern closedir
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func libc_closedir(*syscall.DIR) int
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// FIXME: pathconf returns long, not int.
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//extern pathconf
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func libc_pathconf(*byte, int) int
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func clen(n []byte) int {
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for i := 0; i < len(n); i++ {
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if n[i] == 0 {
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return i
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}
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}
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return len(n)
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}
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var nameMax int32
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func (file *File) readdirnames(n int) (names []string, err error) {
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if file.dirinfo == nil {
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p, err := syscall.BytePtrFromString(file.name)
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if err != nil {
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return nil, err
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}
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elen := int(atomic.LoadInt32(&nameMax))
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if elen == 0 {
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syscall.Entersyscall()
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plen := libc_pathconf(p, syscall.PC_NAME_MAX)
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syscall.Exitsyscall()
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if plen < 1024 {
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plen = 1024
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}
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var dummy syscall.Dirent
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elen = int(unsafe.Offsetof(dummy.Name)) + plen + 1
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atomic.StoreInt32(&nameMax, int32(elen))
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}
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syscall.Entersyscall()
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r := libc_opendir(p)
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errno := syscall.GetErrno()
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syscall.Exitsyscall()
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if r == nil {
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return nil, &PathError{"opendir", file.name, errno}
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}
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file.dirinfo = new(dirInfo)
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file.dirinfo.buf = make([]byte, elen)
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file.dirinfo.dir = r
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}
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entryDirent := (*syscall.Dirent)(unsafe.Pointer(&file.dirinfo.buf[0]))
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size := n
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if size <= 0 {
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size = 100
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n = -1
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}
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names = make([]string, 0, size) // Empty with room to grow.
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for n != 0 {
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var dirent *syscall.Dirent
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pr := &dirent
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syscall.Entersyscall()
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i := libc_readdir_r(file.dirinfo.dir, entryDirent, pr)
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syscall.Exitsyscall()
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if i != 0 {
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return names, NewSyscallError("readdir_r", i)
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}
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if dirent == nil {
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break // EOF
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}
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bytes := (*[10000]byte)(unsafe.Pointer(&dirent.Name[0]))
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var name = string(bytes[0:clen(bytes[:])])
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if name == "." || name == ".." { // Useless names
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continue
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}
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names = append(names, name)
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n--
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}
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if n >= 0 && len(names) == 0 {
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return names, io.EOF
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}
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return names, nil
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}
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