diff options
Diffstat (limited to 'src/pkg/os/file.go')
-rw-r--r-- | src/pkg/os/file.go | 277 |
1 files changed, 36 insertions, 241 deletions
diff --git a/src/pkg/os/file.go b/src/pkg/os/file.go index 3f73f1dff..3aad80234 100644 --- a/src/pkg/os/file.go +++ b/src/pkg/os/file.go @@ -51,14 +51,20 @@ const ( O_RDWR int = syscall.O_RDWR // open the file read-write. O_APPEND int = syscall.O_APPEND // append data to the file when writing. O_ASYNC int = syscall.O_ASYNC // generate a signal when I/O is available. - O_CREAT int = syscall.O_CREAT // create a new file if none exists. - O_EXCL int = syscall.O_EXCL // used with O_CREAT, file must not exist + O_CREATE int = syscall.O_CREAT // create a new file if none exists. + O_EXCL int = syscall.O_EXCL // used with O_CREATE, file must not exist O_NOCTTY int = syscall.O_NOCTTY // do not make file the controlling tty. O_NONBLOCK int = syscall.O_NONBLOCK // open in non-blocking mode. O_NDELAY int = O_NONBLOCK // synonym for O_NONBLOCK O_SYNC int = syscall.O_SYNC // open for synchronous I/O. O_TRUNC int = syscall.O_TRUNC // if possible, truncate file when opened. - O_CREATE int = O_CREAT // create a new file if none exists. +) + +// Seek whence values. +const ( + SEEK_SET int = 0 // seek relative to the origin of the file + SEEK_CUR int = 1 // seek relative to the current offset + SEEK_END int = 2 // seek relative to the end ) type eofError int @@ -83,10 +89,10 @@ func (file *File) Read(b []byte) (n int, err Error) { if n < 0 { n = 0 } - if n == 0 && e == 0 { + if n == 0 && !iserror(e) { return 0, EOF } - if e != 0 { + if iserror(e) { err = &PathError{"read", file.name, Errno(e)} } return n, err @@ -102,10 +108,10 @@ func (file *File) ReadAt(b []byte, off int64) (n int, err Error) { } for len(b) > 0 { m, e := syscall.Pread(file.fd, b, off) - if m == 0 && e == 0 { + if m == 0 && !iserror(e) { return n, EOF } - if e != 0 { + if iserror(e) { err = &PathError{"read", file.name, Errno(e)} break } @@ -127,15 +133,10 @@ func (file *File) Write(b []byte) (n int, err Error) { if n < 0 { n = 0 } - if e == syscall.EPIPE { - file.nepipe++ - if file.nepipe >= 10 { - Exit(syscall.EPIPE) - } - } else { - file.nepipe = 0 - } - if e != 0 { + + epipecheck(file, e) + + if iserror(e) { err = &PathError{"write", file.name, Errno(e)} } return n, err @@ -150,7 +151,7 @@ func (file *File) WriteAt(b []byte, off int64) (n int, err Error) { } for len(b) > 0 { m, e := syscall.Pwrite(file.fd, b, off) - if e != 0 { + if iserror(e) { err = &PathError{"write", file.name, Errno(e)} break } @@ -167,10 +168,10 @@ func (file *File) WriteAt(b []byte, off int64) (n int, err Error) { // It returns the new offset and an Error, if any. func (file *File) Seek(offset int64, whence int) (ret int64, err Error) { r, e := syscall.Seek(file.fd, offset, whence) - if e == 0 && file.dirinfo != nil && r != 0 { + if !iserror(e) && file.dirinfo != nil && r != 0 { e = syscall.EISDIR } - if e != 0 { + if iserror(e) { return 0, &PathError{"seek", file.name, Errno(e)} } return r, nil @@ -187,71 +188,19 @@ func (file *File) WriteString(s string) (ret int, err Error) { return file.Write(b) } -// 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 != 0 { - 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 -} - // Mkdir creates a new directory with the specified name and permission bits. // It returns an error, if any. func Mkdir(name string, perm uint32) Error { e := syscall.Mkdir(name, perm) - if e != 0 { + if iserror(e) { return &PathError{"mkdir", name, Errno(e)} } return 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 e != 0 { - return nil, &PathError{"stat", name, Errno(e)} - } - statp := &lstat - if lstat.Mode&syscall.S_IFMT == syscall.S_IFLNK { - e := syscall.Stat(name, &stat) - if e == 0 { - 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 e != 0 { - return nil, &PathError{"lstat", name, Errno(e)} - } - return fileInfoFromStat(name, new(FileInfo), &stat, &stat), nil -} - // Chdir changes the current working directory to the named directory. func Chdir(dir string) Error { - if e := syscall.Chdir(dir); e != 0 { + if e := syscall.Chdir(dir); iserror(e) { return &PathError{"chdir", dir, Errno(e)} } return nil @@ -260,179 +209,25 @@ func Chdir(dir string) Error { // Chdir changes the current working directory to the file, // which must be a directory. func (f *File) Chdir() Error { - if e := syscall.Fchdir(f.fd); e != 0 { + if e := syscall.Fchdir(f.fd); iserror(e) { return &PathError{"chdir", f.name, Errno(e)} } return 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 e == 0 { - return nil - } - e1 := syscall.Rmdir(name) - if e1 == 0 { - 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() +// Open opens the named file for reading. If successful, methods on +// the returned file can be used for reading; the associated file +// descriptor has mode O_RDONLY. +// It returns the File and an Error, if any. +func Open(name string) (file *File, err Error) { + return OpenFile(name, O_RDONLY, 0) } -// Link creates a hard link. -func Link(oldname, newname string) Error { - e := syscall.Link(oldname, newname) - if e != 0 { - 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 e != 0 { - 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 e != 0 { - 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 e != 0 { - 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); e != 0 { - 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); e != 0 { - 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); e != 0 { - 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); e != 0 { - 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); e != 0 { - 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); e != 0 { - 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); e != 0 { - 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:]); e != 0 { - return &PathError{"chtimes", name, Errno(e)} - } - return nil +// Create creates the named file mode 0666 (before umask), truncating +// it if it already exists. If successful, methods on the returned +// File can be used for I/O; the associated file descriptor has mode +// O_RDWR. +// It returns the File and an Error, if any. +func Create(name string) (file *File, err Error) { + return OpenFile(name, O_RDWR|O_CREATE|O_TRUNC, 0666) } |