1 // Copyright 2009 The Go Authors. All rights reserved. |
1 // Copyright 2009 The Go Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style |
2 // Use of this source code is governed by a BSD-style |
3 // license that can be found in the LICENSE file. |
3 // license that can be found in the LICENSE file. |
4 |
4 |
5 // +build aix darwin dragonfly freebsd linux nacl netbsd openbsd solaris |
5 // +build aix darwin dragonfly freebsd linux netbsd openbsd solaris |
6 |
6 |
7 package unix |
7 package unix |
8 |
8 |
9 import "syscall" |
9 import "unsafe" |
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10 |
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11 // readInt returns the size-bytes unsigned integer in native byte order at offset off. |
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12 func readInt(b []byte, off, size uintptr) (u uint64, ok bool) { |
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13 if len(b) < int(off+size) { |
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14 return 0, false |
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15 } |
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16 if isBigEndian { |
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17 return readIntBE(b[off:], size), true |
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18 } |
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19 return readIntLE(b[off:], size), true |
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20 } |
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21 |
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22 func readIntBE(b []byte, size uintptr) uint64 { |
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23 switch size { |
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24 case 1: |
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25 return uint64(b[0]) |
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26 case 2: |
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27 _ = b[1] // bounds check hint to compiler; see golang.org/issue/14808 |
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28 return uint64(b[1]) | uint64(b[0])<<8 |
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29 case 4: |
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30 _ = b[3] // bounds check hint to compiler; see golang.org/issue/14808 |
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31 return uint64(b[3]) | uint64(b[2])<<8 | uint64(b[1])<<16 | uint64(b[0])<<24 |
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32 case 8: |
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33 _ = b[7] // bounds check hint to compiler; see golang.org/issue/14808 |
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34 return uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 | |
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35 uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56 |
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36 default: |
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37 panic("syscall: readInt with unsupported size") |
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38 } |
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39 } |
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40 |
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41 func readIntLE(b []byte, size uintptr) uint64 { |
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42 switch size { |
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43 case 1: |
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44 return uint64(b[0]) |
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45 case 2: |
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46 _ = b[1] // bounds check hint to compiler; see golang.org/issue/14808 |
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47 return uint64(b[0]) | uint64(b[1])<<8 |
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48 case 4: |
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49 _ = b[3] // bounds check hint to compiler; see golang.org/issue/14808 |
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50 return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 |
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51 case 8: |
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52 _ = b[7] // bounds check hint to compiler; see golang.org/issue/14808 |
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53 return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | |
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54 uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56 |
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55 default: |
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56 panic("syscall: readInt with unsupported size") |
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57 } |
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58 } |
10 |
59 |
11 // ParseDirent parses up to max directory entries in buf, |
60 // ParseDirent parses up to max directory entries in buf, |
12 // appending the names to names. It returns the number of |
61 // appending the names to names. It returns the number of |
13 // bytes consumed from buf, the number of entries added |
62 // bytes consumed from buf, the number of entries added |
14 // to names, and the new names slice. |
63 // to names, and the new names slice. |
15 func ParseDirent(buf []byte, max int, names []string) (consumed int, count int, newnames []string) { |
64 func ParseDirent(buf []byte, max int, names []string) (consumed int, count int, newnames []string) { |
16 return syscall.ParseDirent(buf, max, names) |
65 origlen := len(buf) |
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66 count = 0 |
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67 for max != 0 && len(buf) > 0 { |
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68 reclen, ok := direntReclen(buf) |
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69 if !ok || reclen > uint64(len(buf)) { |
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70 return origlen, count, names |
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71 } |
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72 rec := buf[:reclen] |
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73 buf = buf[reclen:] |
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74 ino, ok := direntIno(rec) |
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75 if !ok { |
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76 break |
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77 } |
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78 if ino == 0 { // File absent in directory. |
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79 continue |
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80 } |
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81 const namoff = uint64(unsafe.Offsetof(Dirent{}.Name)) |
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82 namlen, ok := direntNamlen(rec) |
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83 if !ok || namoff+namlen > uint64(len(rec)) { |
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84 break |
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85 } |
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86 name := rec[namoff : namoff+namlen] |
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87 for i, c := range name { |
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88 if c == 0 { |
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89 name = name[:i] |
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90 break |
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91 } |
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92 } |
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93 // Check for useless names before allocating a string. |
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94 if string(name) == "." || string(name) == ".." { |
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95 continue |
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96 } |
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97 max-- |
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98 count++ |
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99 names = append(names, string(name)) |
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100 } |
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101 return origlen - len(buf), count, names |
17 } |
102 } |