diff options
Diffstat (limited to 'src/pkg/os/file_posix.go')
| -rw-r--r-- | src/pkg/os/file_posix.go | 246 | 
1 files changed, 246 insertions, 0 deletions
| diff --git a/src/pkg/os/file_posix.go b/src/pkg/os/file_posix.go new file mode 100644 index 000000000..5151df498 --- /dev/null +++ b/src/pkg/os/file_posix.go @@ -0,0 +1,246 @@ +// 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. + +// The os package provides a platform-independent interface to operating +// system functionality.  The design is Unix-like. +package os + +import ( +	"syscall" +) + +func epipecheck(file *File, e int) { +	if e == syscall.EPIPE { +		file.nepipe++ +		if file.nepipe >= 10 { +			Exit(syscall.EPIPE) +		} +	} else { +		file.nepipe = 0 +	} +} + + +// Pipe returns a connected pair of Files; reads from r return bytes written to w. +// It returns the files and an Error, if any. +func Pipe() (r *File, w *File, err Error) { +	var p [2]int + +	// See ../syscall/exec.go for description of lock. +	syscall.ForkLock.RLock() +	e := syscall.Pipe(p[0:]) +	if iserror(e) { +		syscall.ForkLock.RUnlock() +		return nil, nil, NewSyscallError("pipe", e) +	} +	syscall.CloseOnExec(p[0]) +	syscall.CloseOnExec(p[1]) +	syscall.ForkLock.RUnlock() + +	return NewFile(p[0], "|0"), NewFile(p[1], "|1"), nil +} + +// Stat returns a FileInfo structure describing the named file and an error, if any. +// If name names a valid symbolic link, the returned FileInfo describes +// the file pointed at by the link and has fi.FollowedSymlink set to true. +// If name names an invalid symbolic link, the returned FileInfo describes +// the link itself and has fi.FollowedSymlink set to false. +func Stat(name string) (fi *FileInfo, err Error) { +	var lstat, stat syscall.Stat_t +	e := syscall.Lstat(name, &lstat) +	if iserror(e) { +		return nil, &PathError{"stat", name, Errno(e)} +	} +	statp := &lstat +	if lstat.Mode&syscall.S_IFMT == syscall.S_IFLNK { +		e := syscall.Stat(name, &stat) +		if !iserror(e) { +			statp = &stat +		} +	} +	return fileInfoFromStat(name, new(FileInfo), &lstat, statp), nil +} + +// Lstat returns the FileInfo structure describing the named file and an +// error, if any.  If the file is a symbolic link, the returned FileInfo +// describes the symbolic link.  Lstat makes no attempt to follow the link. +func Lstat(name string) (fi *FileInfo, err Error) { +	var stat syscall.Stat_t +	e := syscall.Lstat(name, &stat) +	if iserror(e) { +		return nil, &PathError{"lstat", name, Errno(e)} +	} +	return fileInfoFromStat(name, new(FileInfo), &stat, &stat), nil +} + +// Remove removes the named file or directory. +func Remove(name string) Error { +	// System call interface forces us to know +	// whether name is a file or directory. +	// Try both: it is cheaper on average than +	// doing a Stat plus the right one. +	e := syscall.Unlink(name) +	if !iserror(e) { +		return nil +	} +	e1 := syscall.Rmdir(name) +	if !iserror(e1) { +		return nil +	} + +	// Both failed: figure out which error to return. +	// OS X and Linux differ on whether unlink(dir) +	// returns EISDIR, so can't use that.  However, +	// both agree that rmdir(file) returns ENOTDIR, +	// so we can use that to decide which error is real. +	// Rmdir might also return ENOTDIR if given a bad +	// file path, like /etc/passwd/foo, but in that case, +	// both errors will be ENOTDIR, so it's okay to +	// use the error from unlink. +	// For windows syscall.ENOTDIR is set +	// to syscall.ERROR_DIRECTORY, hopefully it should +	// do the trick. +	if e1 != syscall.ENOTDIR { +		e = e1 +	} +	return &PathError{"remove", name, Errno(e)} +} + +// LinkError records an error during a link or symlink or rename +// system call and the paths that caused it. +type LinkError struct { +	Op    string +	Old   string +	New   string +	Error Error +} + +func (e *LinkError) String() string { +	return e.Op + " " + e.Old + " " + e.New + ": " + e.Error.String() +} + +// Link creates a hard link. +func Link(oldname, newname string) Error { +	e := syscall.Link(oldname, newname) +	if iserror(e) { +		return &LinkError{"link", oldname, newname, Errno(e)} +	} +	return nil +} + +// Symlink creates a symbolic link. +func Symlink(oldname, newname string) Error { +	e := syscall.Symlink(oldname, newname) +	if iserror(e) { +		return &LinkError{"symlink", oldname, newname, Errno(e)} +	} +	return nil +} + +// Readlink reads the contents of a symbolic link: the destination of +// the link.  It returns the contents and an Error, if any. +func Readlink(name string) (string, Error) { +	for len := 128; ; len *= 2 { +		b := make([]byte, len) +		n, e := syscall.Readlink(name, b) +		if iserror(e) { +			return "", &PathError{"readlink", name, Errno(e)} +		} +		if n < len { +			return string(b[0:n]), nil +		} +	} +	// Silence 6g. +	return "", nil +} + +// Rename renames a file. +func Rename(oldname, newname string) Error { +	e := syscall.Rename(oldname, newname) +	if iserror(e) { +		return &LinkError{"rename", oldname, newname, Errno(e)} +	} +	return nil +} + +// Chmod changes the mode of the named file to mode. +// If the file is a symbolic link, it changes the mode of the link's target. +func Chmod(name string, mode uint32) Error { +	if e := syscall.Chmod(name, mode); iserror(e) { +		return &PathError{"chmod", name, Errno(e)} +	} +	return nil +} + +// Chmod changes the mode of the file to mode. +func (f *File) Chmod(mode uint32) Error { +	if e := syscall.Fchmod(f.fd, mode); iserror(e) { +		return &PathError{"chmod", f.name, Errno(e)} +	} +	return nil +} + +// Chown changes the numeric uid and gid of the named file. +// If the file is a symbolic link, it changes the uid and gid of the link's target. +func Chown(name string, uid, gid int) Error { +	if e := syscall.Chown(name, uid, gid); iserror(e) { +		return &PathError{"chown", name, Errno(e)} +	} +	return nil +} + +// Lchown changes the numeric uid and gid of the named file. +// If the file is a symbolic link, it changes the uid and gid of the link itself. +func Lchown(name string, uid, gid int) Error { +	if e := syscall.Lchown(name, uid, gid); iserror(e) { +		return &PathError{"lchown", name, Errno(e)} +	} +	return nil +} + +// Chown changes the numeric uid and gid of the named file. +func (f *File) Chown(uid, gid int) Error { +	if e := syscall.Fchown(f.fd, uid, gid); iserror(e) { +		return &PathError{"chown", f.name, Errno(e)} +	} +	return nil +} + +// Truncate changes the size of the file. +// It does not change the I/O offset. +func (f *File) Truncate(size int64) Error { +	if e := syscall.Ftruncate(f.fd, size); iserror(e) { +		return &PathError{"truncate", f.name, Errno(e)} +	} +	return nil +} + +// Sync commits the current contents of the file to stable storage. +// Typically, this means flushing the file system's in-memory copy +// of recently written data to disk. +func (file *File) Sync() (err Error) { +	if file == nil { +		return EINVAL +	} +	if e := syscall.Fsync(file.fd); iserror(e) { +		return NewSyscallError("fsync", e) +	} +	return nil +} + +// Chtimes changes the access and modification times of the named +// file, similar to the Unix utime() or utimes() functions. +// +// The argument times are in nanoseconds, although the underlying +// filesystem may truncate or round the values to a more +// coarse time unit. +func Chtimes(name string, atime_ns int64, mtime_ns int64) Error { +	var utimes [2]syscall.Timeval +	utimes[0] = syscall.NsecToTimeval(atime_ns) +	utimes[1] = syscall.NsecToTimeval(mtime_ns) +	if e := syscall.Utimes(name, utimes[0:]); iserror(e) { +		return &PathError{"chtimes", name, Errno(e)} +	} +	return nil +} | 
