github.com/c12o16h1/go/src@v0.0.0-20200114212001-5a151c0f00ed/os/file_posix.go (about) 1 // Copyright 2009 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 // +build aix darwin dragonfly freebsd js,wasm linux netbsd openbsd solaris windows 6 7 package os 8 9 import ( 10 "syscall" 11 "time" 12 ) 13 14 func sigpipe() // implemented in package runtime 15 16 // syscallMode returns the syscall-specific mode bits from Go's portable mode bits. 17 func syscallMode(i FileMode) (o uint32) { 18 o |= uint32(i.Perm()) 19 if i&ModeSetuid != 0 { 20 o |= syscall.S_ISUID 21 } 22 if i&ModeSetgid != 0 { 23 o |= syscall.S_ISGID 24 } 25 if i&ModeSticky != 0 { 26 o |= syscall.S_ISVTX 27 } 28 // No mapping for Go's ModeTemporary (plan9 only). 29 return 30 } 31 32 // See docs in file.go:Chmod. 33 func chmod(name string, mode FileMode) error { 34 if e := syscall.Chmod(fixLongPath(name), syscallMode(mode)); e != nil { 35 return &PathError{"chmod", name, e} 36 } 37 return nil 38 } 39 40 // See docs in file.go:(*File).Chmod. 41 func (f *File) chmod(mode FileMode) error { 42 if err := f.checkValid("chmod"); err != nil { 43 return err 44 } 45 if e := f.pfd.Fchmod(syscallMode(mode)); e != nil { 46 return f.wrapErr("chmod", e) 47 } 48 return nil 49 } 50 51 // Chown changes the numeric uid and gid of the named file. 52 // If the file is a symbolic link, it changes the uid and gid of the link's target. 53 // A uid or gid of -1 means to not change that value. 54 // If there is an error, it will be of type *PathError. 55 // 56 // On Windows or Plan 9, Chown always returns the syscall.EWINDOWS or 57 // EPLAN9 error, wrapped in *PathError. 58 func Chown(name string, uid, gid int) error { 59 if e := syscall.Chown(name, uid, gid); e != nil { 60 return &PathError{"chown", name, e} 61 } 62 return nil 63 } 64 65 // Lchown changes the numeric uid and gid of the named file. 66 // If the file is a symbolic link, it changes the uid and gid of the link itself. 67 // If there is an error, it will be of type *PathError. 68 // 69 // On Windows, it always returns the syscall.EWINDOWS error, wrapped 70 // in *PathError. 71 func Lchown(name string, uid, gid int) error { 72 if e := syscall.Lchown(name, uid, gid); e != nil { 73 return &PathError{"lchown", name, e} 74 } 75 return nil 76 } 77 78 // Chown changes the numeric uid and gid of the named file. 79 // If there is an error, it will be of type *PathError. 80 // 81 // On Windows, it always returns the syscall.EWINDOWS error, wrapped 82 // in *PathError. 83 func (f *File) Chown(uid, gid int) error { 84 if err := f.checkValid("chown"); err != nil { 85 return err 86 } 87 if e := f.pfd.Fchown(uid, gid); e != nil { 88 return f.wrapErr("chown", e) 89 } 90 return nil 91 } 92 93 // Truncate changes the size of the file. 94 // It does not change the I/O offset. 95 // If there is an error, it will be of type *PathError. 96 func (f *File) Truncate(size int64) error { 97 if err := f.checkValid("truncate"); err != nil { 98 return err 99 } 100 if e := f.pfd.Ftruncate(size); e != nil { 101 return f.wrapErr("truncate", e) 102 } 103 return nil 104 } 105 106 // Sync commits the current contents of the file to stable storage. 107 // Typically, this means flushing the file system's in-memory copy 108 // of recently written data to disk. 109 func (f *File) Sync() error { 110 if err := f.checkValid("sync"); err != nil { 111 return err 112 } 113 if e := f.pfd.Fsync(); e != nil { 114 return f.wrapErr("sync", e) 115 } 116 return nil 117 } 118 119 // Chtimes changes the access and modification times of the named 120 // file, similar to the Unix utime() or utimes() functions. 121 // 122 // The underlying filesystem may truncate or round the values to a 123 // less precise time unit. 124 // If there is an error, it will be of type *PathError. 125 func Chtimes(name string, atime time.Time, mtime time.Time) error { 126 var utimes [2]syscall.Timespec 127 utimes[0] = syscall.NsecToTimespec(atime.UnixNano()) 128 utimes[1] = syscall.NsecToTimespec(mtime.UnixNano()) 129 if e := syscall.UtimesNano(fixLongPath(name), utimes[0:]); e != nil { 130 return &PathError{"chtimes", name, e} 131 } 132 return nil 133 } 134 135 // Chdir changes the current working directory to the file, 136 // which must be a directory. 137 // If there is an error, it will be of type *PathError. 138 func (f *File) Chdir() error { 139 if err := f.checkValid("chdir"); err != nil { 140 return err 141 } 142 if e := f.pfd.Fchdir(); e != nil { 143 return f.wrapErr("chdir", e) 144 } 145 return nil 146 } 147 148 // setDeadline sets the read and write deadline. 149 func (f *File) setDeadline(t time.Time) error { 150 if err := f.checkValid("SetDeadline"); err != nil { 151 return err 152 } 153 return f.pfd.SetDeadline(t) 154 } 155 156 // setReadDeadline sets the read deadline. 157 func (f *File) setReadDeadline(t time.Time) error { 158 if err := f.checkValid("SetReadDeadline"); err != nil { 159 return err 160 } 161 return f.pfd.SetReadDeadline(t) 162 } 163 164 // setWriteDeadline sets the write deadline. 165 func (f *File) setWriteDeadline(t time.Time) error { 166 if err := f.checkValid("SetWriteDeadline"); err != nil { 167 return err 168 } 169 return f.pfd.SetWriteDeadline(t) 170 } 171 172 // checkValid checks whether f is valid for use. 173 // If not, it returns an appropriate error, perhaps incorporating the operation name op. 174 func (f *File) checkValid(op string) error { 175 if f == nil { 176 return ErrInvalid 177 } 178 return nil 179 }