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Diffstat (limited to 'src/os/types.go')
-rw-r--r-- | src/os/types.go | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/src/os/types.go b/src/os/types.go new file mode 100644 index 000000000..473d431d4 --- /dev/null +++ b/src/os/types.go @@ -0,0 +1,118 @@ +// 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 ( + "syscall" + "time" +) + +// Getpagesize returns the underlying system's memory page size. +func Getpagesize() int { return syscall.Getpagesize() } + +// A FileInfo describes a file and is returned by Stat and Lstat. +type FileInfo interface { + Name() string // base name of the file + Size() int64 // length in bytes for regular files; system-dependent for others + Mode() FileMode // file mode bits + ModTime() time.Time // modification time + IsDir() bool // abbreviation for Mode().IsDir() + Sys() interface{} // underlying data source (can return nil) +} + +// A FileMode represents a file's mode and permission bits. +// The bits have the same definition on all systems, so that +// information about files can be moved from one system +// to another portably. Not all bits apply to all systems. +// The only required bit is ModeDir for directories. +type FileMode uint32 + +// The defined file mode bits are the most significant bits of the FileMode. +// The nine least-significant bits are the standard Unix rwxrwxrwx permissions. +// The values of these bits should be considered part of the public API and +// may be used in wire protocols or disk representations: they must not be +// changed, although new bits might be added. +const ( + // The single letters are the abbreviations + // used by the String method's formatting. + ModeDir FileMode = 1 << (32 - 1 - iota) // d: is a directory + ModeAppend // a: append-only + ModeExclusive // l: exclusive use + ModeTemporary // T: temporary file (not backed up) + ModeSymlink // L: symbolic link + ModeDevice // D: device file + ModeNamedPipe // p: named pipe (FIFO) + ModeSocket // S: Unix domain socket + ModeSetuid // u: setuid + ModeSetgid // g: setgid + ModeCharDevice // c: Unix character device, when ModeDevice is set + ModeSticky // t: sticky + + // Mask for the type bits. For regular files, none will be set. + ModeType = ModeDir | ModeSymlink | ModeNamedPipe | ModeSocket | ModeDevice + + ModePerm FileMode = 0777 // permission bits +) + +func (m FileMode) String() string { + const str = "dalTLDpSugct" + var buf [32]byte // Mode is uint32. + w := 0 + for i, c := range str { + if m&(1<<uint(32-1-i)) != 0 { + buf[w] = byte(c) + w++ + } + } + if w == 0 { + buf[w] = '-' + w++ + } + const rwx = "rwxrwxrwx" + for i, c := range rwx { + if m&(1<<uint(9-1-i)) != 0 { + buf[w] = byte(c) + } else { + buf[w] = '-' + } + w++ + } + return string(buf[:w]) +} + +// IsDir reports whether m describes a directory. +// That is, it tests for the ModeDir bit being set in m. +func (m FileMode) IsDir() bool { + return m&ModeDir != 0 +} + +// IsRegular reports whether m describes a regular file. +// That is, it tests that no mode type bits are set. +func (m FileMode) IsRegular() bool { + return m&ModeType == 0 +} + +// Perm returns the Unix permission bits in m. +func (m FileMode) Perm() FileMode { + return m & ModePerm +} + +func (fs *fileStat) Name() string { return fs.name } +func (fs *fileStat) IsDir() bool { return fs.Mode().IsDir() } + +// SameFile reports whether fi1 and fi2 describe the same file. +// For example, on Unix this means that the device and inode fields +// of the two underlying structures are identical; on other systems +// the decision may be based on the path names. +// SameFile only applies to results returned by this package's Stat. +// It returns false in other cases. +func SameFile(fi1, fi2 FileInfo) bool { + fs1, ok1 := fi1.(*fileStat) + fs2, ok2 := fi2.(*fileStat) + if !ok1 || !ok2 { + return false + } + return sameFile(fs1, fs2) +} |