// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
+// +build darwin freebsd linux netbsd openbsd
+
package os
import (
"runtime"
+ "sync/atomic"
"syscall"
)
+// File represents an open file descriptor.
+type File struct {
+ *file
+}
+
+// file is the real representation of *File.
+// The extra level of indirection ensures that no clients of os
+// can overwrite this data, which could cause the finalizer
+// to close the wrong file descriptor.
+type file struct {
+ fd int
+ name string
+ dirinfo *dirInfo // nil unless directory being read
+ nepipe int32 // number of consecutive EPIPE in Write
+}
+
+// Fd returns the integer Unix file descriptor referencing the open file.
+func (f *File) Fd() uintptr {
+ if f == nil {
+ return ^(uintptr(0))
+ }
+ return uintptr(f.fd)
+}
+
+// NewFile returns a new File with the given file descriptor and name.
+func NewFile(fd uintptr, name string) *File {
+ fdi := int(fd)
+ if fdi < 0 {
+ return nil
+ }
+ f := &File{&file{fd: fdi, name: name}}
+ runtime.SetFinalizer(f.file, (*file).close)
+ return f
+}
+
// Auxiliary information if the File describes a directory
type dirInfo struct {
- buf []byte // buffer for directory I/O
+ buf []byte // buffer for directory I/O
dir *syscall.DIR // from opendir
}
+func epipecheck(file *File, e error) {
+ if e == syscall.EPIPE {
+ if atomic.AddInt32(&file.nepipe, 1) >= 10 {
+ sigpipe()
+ }
+ } else {
+ atomic.StoreInt32(&file.nepipe, 0)
+ }
+}
+
// DevNull is the name of the operating system's ``null device.''
// On Unix-like systems, it is "/dev/null"; on Windows, "NUL".
const DevNull = "/dev/null"
-// Open opens the named file with specified flag (O_RDONLY etc.) and perm, (0666 etc.)
-// if applicable. If successful, methods on the returned File can be used for I/O.
-// It returns the File and an Error, if any.
-func Open(name string, flag int, perm uint32) (file *File, err Error) {
- r, e := syscall.Open(name, flag|syscall.O_CLOEXEC, perm)
- if e != 0 {
- return nil, &PathError{"open", name, Errno(e)}
+// OpenFile is the generalized open call; most users will use Open
+// or Create instead. It opens the named file with specified flag
+// (O_RDONLY etc.) and perm, (0666 etc.) if applicable. If successful,
+// methods on the returned File can be used for I/O.
+// If there is an error, it will be of type *PathError.
+func OpenFile(name string, flag int, perm FileMode) (file *File, err error) {
+ r, e := syscall.Open(name, flag|syscall.O_CLOEXEC, syscallMode(perm))
+ if e != nil {
+ return nil, &PathError{"open", name, e}
}
// There's a race here with fork/exec, which we are
- // content to live with. See ../syscall/exec.go
- if syscall.O_CLOEXEC == 0 { // O_CLOEXEC not supported
+ // content to live with. See ../syscall/exec_unix.go.
+ // On OS X 10.6, the O_CLOEXEC flag is not respected.
+ // On OS X 10.7, the O_CLOEXEC flag works.
+ // Without a cheap & reliable way to detect 10.6 vs 10.7 at
+ // runtime, we just always call syscall.CloseOnExec on Darwin.
+ // Once >=10.7 is prevalent, this extra call can removed.
+ if syscall.O_CLOEXEC == 0 || runtime.GOOS == "darwin" { // O_CLOEXEC not supported
syscall.CloseOnExec(r)
}
- return NewFile(r, name), nil
+ return NewFile(uintptr(r), name), nil
}
// Close closes the File, rendering it unusable for I/O.
-// It returns an Error, if any.
-func (file *File) Close() Error {
+// It returns an error, if any.
+func (f *File) Close() error {
+ return f.file.close()
+}
+
+func (file *file) close() error {
if file == nil || file.fd < 0 {
- return EINVAL
+ return syscall.EINVAL
+ }
+ var err error
+ if e := syscall.Close(file.fd); e != nil {
+ err = &PathError{"close", file.name, e}
}
- var err Error
- if e := syscall.Close(file.fd); e != 0 {
- err = &PathError{"close", file.name, Errno(e)}
+
+ if file.dirinfo != nil {
+ if libc_closedir(file.dirinfo.dir) < 0 && err == nil {
+ err = &PathError{"closedir", file.name, syscall.GetErrno()}
+ }
}
+
file.fd = -1 // so it can't be closed again
// no need for a finalizer anymore
}
// Stat returns the FileInfo structure describing file.
-// It returns the FileInfo and an error, if any.
-func (file *File) Stat() (fi *FileInfo, err Error) {
+// If there is an error, it will be of type *PathError.
+func (f *File) Stat() (fi FileInfo, err error) {
+ var stat syscall.Stat_t
+ err = syscall.Fstat(f.fd, &stat)
+ if err != nil {
+ return nil, &PathError{"stat", f.name, err}
+ }
+ return fileInfoFromStat(&stat, f.name), nil
+}
+
+// Stat returns a FileInfo describing the named file.
+// If there is an error, it will be of type *PathError.
+func Stat(name string) (fi FileInfo, err error) {
+ var stat syscall.Stat_t
+ err = syscall.Stat(name, &stat)
+ if err != nil {
+ return nil, &PathError{"stat", name, err}
+ }
+ return fileInfoFromStat(&stat, name), nil
+}
+
+// Lstat returns a FileInfo describing the named file.
+// If the file is a symbolic link, the returned FileInfo
+// describes the symbolic link. Lstat makes no attempt to follow the link.
+// If there is an error, it will be of type *PathError.
+func Lstat(name string) (fi FileInfo, err error) {
var stat syscall.Stat_t
- e := syscall.Fstat(file.fd, &stat)
- if e != 0 {
- return nil, &PathError{"stat", file.name, Errno(e)}
+ err = syscall.Lstat(name, &stat)
+ if err != nil {
+ return nil, &PathError{"lstat", name, err}
}
- return fileInfoFromStat(file.name, new(FileInfo), &stat, &stat), nil
+ return fileInfoFromStat(&stat, name), nil
}
-// Readdir reads the contents of the directory associated with file and
-// returns an array of up to count FileInfo structures, as would be returned
-// by Lstat, in directory order. Subsequent calls on the same file will yield
-// further FileInfos.
-// A negative count means to read until EOF.
-// Readdir returns the array and an Error, if any.
-func (file *File) Readdir(count int) (fi []FileInfo, err Error) {
- dirname := file.name
+func (f *File) readdir(n int) (fi []FileInfo, err error) {
+ dirname := f.name
if dirname == "" {
dirname = "."
}
dirname += "/"
- names, err1 := file.Readdirnames(count)
- if err1 != nil {
- return nil, err1
- }
+ names, err := f.Readdirnames(n)
fi = make([]FileInfo, len(names))
for i, filename := range names {
fip, err := Lstat(dirname + filename)
- if fip == nil || err != nil {
- fi[i].Name = filename // rest is already zeroed out
+ if err == nil {
+ fi[i] = fip
} else {
- fi[i] = *fip
+ fi[i] = &fileStat{name: filename}
+ }
+ }
+ return fi, err
+}
+
+// read reads up to len(b) bytes from the File.
+// It returns the number of bytes read and an error, if any.
+func (f *File) read(b []byte) (n int, err error) {
+ return syscall.Read(f.fd, b)
+}
+
+// pread reads len(b) bytes from the File starting at byte offset off.
+// It returns the number of bytes read and the error, if any.
+// EOF is signaled by a zero count with err set to 0.
+func (f *File) pread(b []byte, off int64) (n int, err error) {
+ return syscall.Pread(f.fd, b, off)
+}
+
+// write writes len(b) bytes to the File.
+// It returns the number of bytes written and an error, if any.
+func (f *File) write(b []byte) (n int, err error) {
+ for {
+ m, err := syscall.Write(f.fd, b)
+ n += m
+
+ // If the syscall wrote some data but not all (short write)
+ // or it returned EINTR, then assume it stopped early for
+ // reasons that are uninteresting to the caller, and try again.
+ if 0 < m && m < len(b) || err == syscall.EINTR {
+ b = b[m:]
+ continue
}
+
+ return n, err
}
- return
+ panic("not reached")
+}
+
+// pwrite writes len(b) bytes to the File starting at byte offset off.
+// It returns the number of bytes written and an error, if any.
+func (f *File) pwrite(b []byte, off int64) (n int, err error) {
+ return syscall.Pwrite(f.fd, b, off)
+}
+
+// seek sets the offset for the next Read or Write on file to offset, interpreted
+// according to whence: 0 means relative to the origin of the file, 1 means
+// relative to the current offset, and 2 means relative to the end.
+// It returns the new offset and an error, if any.
+func (f *File) seek(offset int64, whence int) (ret int64, err error) {
+ return syscall.Seek(f.fd, offset, whence)
}
// Truncate changes the size of the named file.
// If the file is a symbolic link, it changes the size of the link's target.
-func Truncate(name string, size int64) Error {
- if e := syscall.Truncate(name, size); e != 0 {
- return &PathError{"truncate", name, Errno(e)}
+// If there is an error, it will be of type *PathError.
+func Truncate(name string, size int64) error {
+ if e := syscall.Truncate(name, size); e != nil {
+ return &PathError{"truncate", name, e}
}
return nil
}
+
+// Remove removes the named file or directory.
+// If there is an error, it will be of type *PathError.
+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 e == nil {
+ return nil
+ }
+ e1 := syscall.Rmdir(name)
+ if e1 == nil {
+ 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.
+ if e1 != syscall.ENOTDIR {
+ e = e1
+ }
+ return &PathError{"remove", name, e}
+}
+
+// basename removes trailing slashes and the leading directory name from path name
+func basename(name string) string {
+ i := len(name) - 1
+ // Remove trailing slashes
+ for ; i > 0 && name[i] == '/'; i-- {
+ name = name[:i]
+ }
+ // Remove leading directory name
+ for i--; i >= 0; i-- {
+ if name[i] == '/' {
+ name = name[i+1:]
+ break
+ }
+ }
+
+ return name
+}
+
+// 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 e != nil {
+ syscall.ForkLock.RUnlock()
+ return nil, nil, NewSyscallError("pipe", e)
+ }
+ syscall.CloseOnExec(p[0])
+ syscall.CloseOnExec(p[1])
+ syscall.ForkLock.RUnlock()
+
+ return NewFile(uintptr(p[0]), "|0"), NewFile(uintptr(p[1]), "|1"), nil
+}
+
+// TempDir returns the default directory to use for temporary files.
+func TempDir() string {
+ dir := Getenv("TMPDIR")
+ if dir == "" {
+ dir = "/tmp"
+ }
+ return dir
+}
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