types.go

     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  package os
     6  
     7  import (
     8  	"io/fs"
     9  	"syscall"
    10  )
    11  
    12  // Getpagesize returns the underlying system's memory page size.
    13  func Getpagesize() int { return syscall.Getpagesize() }
    14  
    15  // File represents an open file descriptor.
    16  //
    17  // The methods of File are safe for concurrent use.
    18  type File struct {
    19  	*file // os specific
    20  }
    21  
    22  // A FileInfo describes a file and is returned by [Stat] and [Lstat].
    23  type FileInfo = fs.FileInfo
    24  
    25  // A FileMode represents a file's mode and permission bits.
    26  // The bits have the same definition on all systems, so that
    27  // information about files can be moved from one system
    28  // to another portably. Not all bits apply to all systems.
    29  // The only required bit is [ModeDir] for directories.
    30  type FileMode = fs.FileMode
    31  
    32  // The defined file mode bits are the most significant bits of the [FileMode].
    33  // The nine least-significant bits are the standard Unix rwxrwxrwx permissions.
    34  // The values of these bits should be considered part of the public API and
    35  // may be used in wire protocols or disk representations: they must not be
    36  // changed, although new bits might be added.
    37  const (
    38  	// The single letters are the abbreviations
    39  	// used by the String method's formatting.
    40  	ModeDir        = fs.ModeDir        // d: is a directory
    41  	ModeAppend     = fs.ModeAppend     // a: append-only
    42  	ModeExclusive  = fs.ModeExclusive  // l: exclusive use
    43  	ModeTemporary  = fs.ModeTemporary  // T: temporary file; Plan 9 only
    44  	ModeSymlink    = fs.ModeSymlink    // L: symbolic link
    45  	ModeDevice     = fs.ModeDevice     // D: device file
    46  	ModeNamedPipe  = fs.ModeNamedPipe  // p: named pipe (FIFO)
    47  	ModeSocket     = fs.ModeSocket     // S: Unix domain socket
    48  	ModeSetuid     = fs.ModeSetuid     // u: setuid
    49  	ModeSetgid     = fs.ModeSetgid     // g: setgid
    50  	ModeCharDevice = fs.ModeCharDevice // c: Unix character device, when ModeDevice is set
    51  	ModeSticky     = fs.ModeSticky     // t: sticky
    52  	ModeIrregular  = fs.ModeIrregular  // ?: non-regular file; nothing else is known about this file
    53  
    54  	// Mask for the type bits. For regular files, none will be set.
    55  	ModeType = fs.ModeType
    56  
    57  	ModePerm = fs.ModePerm // Unix permission bits, 0o777
    58  )
    59  
    60  func (fs *fileStat) Name() string { return fs.name }
    61  func (fs *fileStat) IsDir() bool  { return fs.Mode().IsDir() }
    62  
    63  // SameFile reports whether fi1 and fi2 describe the same file.
    64  // For example, on Unix this means that the device and inode fields
    65  // of the two underlying structures are identical; on other systems
    66  // the decision may be based on the path names.
    67  // SameFile only applies to results returned by this package's [Stat].
    68  // It returns false in other cases.
    69  func SameFile(fi1, fi2 FileInfo) bool {
    70  	fs1, ok1 := fi1.(*fileStat)
    71  	fs2, ok2 := fi2.(*fileStat)
    72  	if !ok1 || !ok2 {
    73  		return false
    74  	}
    75  	return sameFile(fs1, fs2)
    76  }
    77
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