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103 lines
3.1 KiB
103 lines
3.1 KiB
// 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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//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris |
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// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris |
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package unix |
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import "unsafe" |
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// readInt returns the size-bytes unsigned integer in native byte order at offset off. |
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func readInt(b []byte, off, size uintptr) (u uint64, ok bool) { |
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if len(b) < int(off+size) { |
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return 0, false |
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} |
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if isBigEndian { |
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return readIntBE(b[off:], size), true |
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} |
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return readIntLE(b[off:], size), true |
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} |
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func readIntBE(b []byte, size uintptr) uint64 { |
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switch size { |
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case 1: |
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return uint64(b[0]) |
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case 2: |
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_ = b[1] // bounds check hint to compiler; see golang.org/issue/14808 |
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return uint64(b[1]) | uint64(b[0])<<8 |
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case 4: |
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_ = b[3] // bounds check hint to compiler; see golang.org/issue/14808 |
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return uint64(b[3]) | uint64(b[2])<<8 | uint64(b[1])<<16 | uint64(b[0])<<24 |
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case 8: |
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_ = b[7] // bounds check hint to compiler; see golang.org/issue/14808 |
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return uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 | |
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uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56 |
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default: |
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panic("syscall: readInt with unsupported size") |
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} |
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} |
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func readIntLE(b []byte, size uintptr) uint64 { |
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switch size { |
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case 1: |
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return uint64(b[0]) |
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case 2: |
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_ = b[1] // bounds check hint to compiler; see golang.org/issue/14808 |
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return uint64(b[0]) | uint64(b[1])<<8 |
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case 4: |
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_ = b[3] // bounds check hint to compiler; see golang.org/issue/14808 |
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return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 |
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case 8: |
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_ = b[7] // bounds check hint to compiler; see golang.org/issue/14808 |
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return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | |
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uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56 |
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default: |
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panic("syscall: readInt with unsupported size") |
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} |
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} |
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// ParseDirent parses up to max directory entries in buf, |
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// appending the names to names. It returns the number of |
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// bytes consumed from buf, the number of entries added |
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// to names, and the new names slice. |
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func ParseDirent(buf []byte, max int, names []string) (consumed int, count int, newnames []string) { |
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origlen := len(buf) |
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count = 0 |
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for max != 0 && len(buf) > 0 { |
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reclen, ok := direntReclen(buf) |
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if !ok || reclen > uint64(len(buf)) { |
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return origlen, count, names |
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} |
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rec := buf[:reclen] |
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buf = buf[reclen:] |
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ino, ok := direntIno(rec) |
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if !ok { |
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break |
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} |
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if ino == 0 { // File absent in directory. |
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continue |
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} |
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const namoff = uint64(unsafe.Offsetof(Dirent{}.Name)) |
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namlen, ok := direntNamlen(rec) |
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if !ok || namoff+namlen > uint64(len(rec)) { |
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break |
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} |
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name := rec[namoff : namoff+namlen] |
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for i, c := range name { |
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if c == 0 { |
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name = name[:i] |
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break |
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} |
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} |
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// Check for useless names before allocating a string. |
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if string(name) == "." || string(name) == ".." { |
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continue |
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} |
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max-- |
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count++ |
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names = append(names, string(name)) |
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} |
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return origlen - len(buf), count, names |
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}
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