file.n

tcl是工具命令语言

\fI-linktype\fR are "-symbolic" and "-hard".
.
When creating links on filesystems that either do not support any links,
or do not support the specific type requested, an error message will be
returned.  In particular Windows 95, 98 and ME do not support any links
at present, but most Unix platforms support both symbolic and hard links
(the latter for files only), MacOS supports symbolic links and Windows
NT/2000/XP (on NTFS drives) support symbolic directory links and hard
file links.
.TP
\fBfile lstat \fIname varName\fR
.
Same as \fBstat\fR option (see below) except uses the \fIlstat\fR
kernel call instead of \fIstat\fR.  This means that if \fIname\fR
refers to a symbolic link the information returned in \fIvarName\fR
is for the link rather than the file it refers to.  On systems that
don't support symbolic links this option behaves exactly the same
as the \fBstat\fR option.
.TP
\fBfile mkdir \fIdir\fR ?\fIdir\fR ...?
.
Creates each directory specified.  For each pathname \fIdir\fR specified,
this command will create all non-existing parent directories as
well as \fIdir\fR itself.  If an existing directory is specified, then
no action is taken and no error is returned.  Trying to overwrite an existing
file with a directory will result in an error.  Arguments are processed in
the order specified, halting at the first error, if any.
.TP
\fBfile mtime \fIname\fR ?\fItime\fR?
.
Returns a decimal string giving the time at which file \fIname\fR was last
modified.  If \fItime\fR is specified, it is a modification time to set for
the file (equivalent to Unix \fBtouch\fR).  The time is measured in the
standard POSIX fashion as seconds from a fixed starting time (often January
1, 1970).  If the file doesn't exist or its modified time cannot be queried
or set then an error is generated.
.TP
\fBfile nativename \fIname\fR
.
Returns the platform-specific name of the file. This is useful if the
filename is needed to pass to a platform-specific call, such as exec
under Windows or AppleScript on the Macintosh.
.TP
\fBfile normalize \fIname\fR
.
.RS
Returns a unique normalised path representation for the file-system
object (file, directory, link, etc), whose string value can be used as a
unique identifier for it.  A normalized path is an absolute path which has
all '../', './' removed.  Also it is one which is in the ``standard''
format for the native platform.  On MacOS, Unix, this means the segments
leading up to the path must be free of symbolic links/aliases (but the
very last path component may be a symbolic link), and on Windows it also
means means we want the long form with that form's case-dependence (which
gives us a unique, case-dependent path).  The one exception concerning the
last link in the path is necessary, because Tcl or the user may wish to
operate on the actual symbolic link itself (for example 'file delete', 'file
rename', 'file copy' are defined to operate on symbolic links, not on the
things that they point to).
.RE
.TP
\fBfile owned \fIname\fR 
.
Returns \fB1\fR if file \fIname\fR is owned by the current user, \fB0\fR
otherwise.
.TP
\fBfile pathtype \fIname\fR
.
Returns one of \fBabsolute\fR, \fBrelative\fR, \fBvolumerelative\fR.  If
\fIname\fR refers to a specific file on a specific volume, the path type
will be \fBabsolute\fR.  If \fIname\fR refers to a file relative to the
current working directory, then the path type will be \fBrelative\fR.  If
\fIname\fR refers to a file relative to the current working directory on
a specified volume, or to a specific file on the current working volume, then
the file type is \fBvolumerelative\fR.
.TP
\fBfile readable \fIname\fR
.
Returns \fB1\fR if file \fIname\fR is readable by the current user,
\fB0\fR otherwise. 
.TP
\fBfile readlink \fIname\fR
.
Returns the value of the symbolic link given by \fIname\fR (i.e. the name
of the file it points to).  If \fIname\fR isn't a symbolic link or its
value cannot be read, then an error is returned.  On systems that don't
support symbolic links this option is undefined.
.TP
\fBfile rename \fR?\fB\-force\fR? ?\fB\-\|\-\fR? \fIsource\fR \fItarget\fR
.TP
\fBfile rename \fR?\fB\-force\fR? ?\fB\-\|\-\fR? \fIsource\fR ?\fIsource\fR ...? \fItargetDir\fR
.RS
The first form takes the file or directory specified by pathname
\fIsource\fR and renames it to \fItarget\fR, moving the file if the
pathname \fItarget\fR specifies a name in a different directory.  If
\fItarget\fR is an existing directory, then the second form is used.
The second form moves each \fIsource\fR file or directory into the
directory \fItargetDir\fR. Existing files will not be overwritten
unless the \fB\-force\fR option is specified.  When operating inside a
single filesystem, Tcl will rename symbolic links rather than the
things that they point to.  Trying to overwrite a non-empty directory,
overwrite a directory with a file, or a file with a directory will all
result in errors.  Arguments are processed in the order specified,
halting at the first error, if any.  A \fB\-\|\-\fR marks the end of
switches; the argument following the \fB\-\|\-\fR will be treated as a
\fIsource\fR even if it starts with a \fB\-\fR.
.RE
.TP
\fBfile rootname \fIname\fR
.
Returns all of the characters in \fIname\fR up to but not including the
last ``.'' character in the last component of name.  If the last
component of \fIname\fR doesn't contain a dot, then returns \fIname\fR.
.TP
\fBfile separator\fR ?\fIname\fR?
.
If no argument is given, returns the character which is used to separate 
path segments for native files on this platform.  If a path is given,
the filesystem responsible for that path is asked to return its
separator character.  If no file system accepts \fIname\fR, an error
is generated.
.TP
\fBfile size \fIname\fR
.
Returns a decimal string giving the size of file \fIname\fR in bytes.  If
the file doesn't exist or its size cannot be queried then an error is
generated.
.TP
\fBfile split \fIname\fR
.
Returns a list whose elements are the path components in \fIname\fR.  The
first element of the list will have the same path type as \fIname\fR.
All other elements will be relative.  Path separators will be discarded
unless they are needed ensure that an element is unambiguously relative.
For example, under Unix
.RS
.CS
file split /foo/~bar/baz
.CE
returns \fB/\0\0foo\0\0./~bar\0\0baz\fR to ensure that later commands
that use the third component do not attempt to perform tilde
substitution.
.RE
.TP
\fBfile stat  \fIname varName\fR
.
Invokes the \fBstat\fR kernel call on \fIname\fR, and uses the variable
given by \fIvarName\fR to hold information returned from the kernel call.
\fIVarName\fR is treated as an array variable, and the following elements
of that variable are set: \fBatime\fR, \fBctime\fR, \fBdev\fR, \fBgid\fR,
\fBino\fR, \fBmode\fR, \fBmtime\fR, \fBnlink\fR, \fBsize\fR, \fBtype\fR,
\fBuid\fR.  Each element except \fBtype\fR is a decimal string with the
value of the corresponding field from the \fBstat\fR return structure;
see the manual entry for \fBstat\fR for details on the meanings of the
values.  The \fBtype\fR element gives the type of the file in the same
form returned by the command \fBfile type\fR.  This command returns an
empty string.
.TP
\fBfile system \fIname\fR
.
Returns a list of two elements, the first of which is the name of the
filesystem to use for the file, and the second an arbitrary string
representing the filesystem-specific nature or type of the location
within that filesystem.  If a filesystem only supports one type of file,
the second element may be null.  For example the native files have a
first element 'native', and a second element which is a platform-specific
type name for the file's system (e.g. 'NTFS', 'FAT', etc), or possibly
the empty string if no further information is available or if this
is not implemented.  A generic virtual file system might return the
list 'vfs ftp' to represent a file on a remote ftp site mounted as a
virtual filesystem through an extension called 'vfs'.  If the file does
not belong to any filesystem, an error is generated.
.TP
\fBfile tail \fIname\fR
.
Returns all of the characters in \fIname\fR after the last directory
separator.  If \fIname\fR contains no separators then returns
\fIname\fR.
.TP
\fBfile type \fIname\fR
.
Returns a string giving the type of file \fIname\fR, which will be one of
\fBfile\fR, \fBdirectory\fR, \fBcharacterSpecial\fR, \fBblockSpecial\fR,
\fBfifo\fR, \fBlink\fR, or \fBsocket\fR.
.TP
\fBfile volumes\fR
. 
Returns the absolute paths to the volumes mounted on the system, as a
proper Tcl list.  On the Macintosh, this will be a list of the mounted
drives, both local and network.  N.B. if two drives have the same name,
they will both appear on the volume list, but there is currently no way,
from Tcl, to access any but the first of these drives.  On UNIX, the
command will always return "/", since all filesystems are locally mounted.
On Windows, it will return a list of the available local drives
(e.g. {a:/ c:/}).
.TP
\fBfile writable \fIname\fR
.
Returns \fB1\fR if file \fIname\fR is writable by the current user,
\fB0\fR otherwise.
.SH "PORTABILITY ISSUES"
.TP
\fBUnix\fR\0\0\0\0\0\0\0
.
These commands always operate using the real user and group identifiers,
not the effective ones. 

.SH "SEE ALSO"
filename(n), open(n), close(n), eof(n), gets(n), tell(n), seek(n),
fblocked(n), flush(n)

.SH KEYWORDS
attributes, copy files, delete files, directory, file, move files, name, rename files, stat