Tcl Built-In Commands - file manual page

This command provides several operations on a file's name or attributes. Name is the name of a file; if it starts with a tilde, then tilde substitution is done before executing the command (see the manual entry for filename for details). Option indicates what to do with the file name. Any unique abbreviation for option is acceptable. The valid options are:

file atime name ?time?

Returns a decimal string giving the time at which file name was last accessed. If time is specified, it is an access time to set for the file. 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 access time cannot be queried or set then an error is generated. On Windows, FAT file systems do not support access time.

file attributes name

file attributes name ?option?
file attributes name ?option value option value...?

This subcommand returns or sets platform specific values associated with a file. The first form returns a list of the platform specific flags and their values. The second form returns the value for the specific option. The third form sets one or more of the values. The values are as follows:

On Unix, -group gets or sets the group name for the file. A group id can be given to the command, but it returns a group name. -owner gets or sets the user name of the owner of the file. The command returns the owner name, but the numerical id can be passed when setting the owner. -permissions sets or retrieves the octal code that chmod(1) uses. This command does also has limited support for setting using the symbolic attributes for chmod(1), of the form [ugo]?[[+-=][rwxst],[...]], where multiple symbolic attributes can be separated by commas (example: u+s,go-rw add sticky bit for user, remove read and write permissions for group and other). A simplified ls style string, of the form rwxrwxrwx (must be 9 characters), is also supported (example: rwxr-xr-t is equivalent to 01755).

On Windows, -archive gives the value or sets or clears the archive attribute of the file. -hidden gives the value or sets or clears the hidden attribute of the file. -longname will expand each path element to its long version. This attribute cannot be set. -readonly gives the value or sets or clears the readonly attribute of the file. -shortname gives a string where every path element is replaced with its short (8.3) version of the name. This attribute cannot be set. -system gives or sets or clears the value of the system attribute of the file.

On Macintosh, -creator gives or sets the Finder creator type of the file. -hidden gives or sets or clears the hidden attribute of the file. -readonly gives or sets or clears the readonly attribute of the file. Note that directories can only be locked if File Sharing is turned on. -type gives or sets the Finder file type for the file.

file channels ?pattern?

If pattern isn't specified, returns a list of names of all registered open channels in this interpreter. If pattern is specified, only those names matching pattern are returned. Matching is determined using the same rules as for string match.

file copy ?-force? ?- -? source target

file copy ?-force? ?- -? source ?source ...? targetDir

The first form makes a copy of the file or directory source under the pathname target. If target is an existing directory, then the second form is used. The second form makes a copy inside targetDir of each source file listed. If a directory is specified as a source, then the contents of the directory will be recursively copied into targetDir. Existing files will not be overwritten unless the -force option is specified. Trying to overwrite a non-empty directory, overwrite a directory with a file, or a file with a directory will all result in errors even if -force was specified. Arguments are processed in the order specified, halting at the first error, if any. A - - marks the end of switches; the argument following the - - will be treated as a source even if it starts with a -.

file delete ?-force? ?- -? pathname ?pathname ... ?

Removes the file or directory specified by each pathname argument. Non-empty directories will be removed only if the -force option is specified. Trying to delete a non-existant file is not considered an error. Trying to delete a read-only file will cause the file to be deleted, even if the -force flags is not specified. Arguments are processed in the order specified, halting at the first error, if any. A - - marks the end of switches; the argument following the - - will be treated as a pathname even if it starts with a -.

file dirname name

Returns a name comprised of all of the path components in name excluding the last element. If name is a relative file name and only contains one path element, then returns ``.'' (or ``:'' on the Macintosh). If name refers to a root directory, then the root directory is returned. For example,

file dirname c:/

returns c:/.

Note that tilde substitution will only be performed if it is necessary to complete the command. For example,

file dirname ~/src/foo.c

returns ~/src, whereas

file dirname ~

returns /home (or something similar).

file executable name

Returns 1 if file name is executable by the current user, 0 otherwise.

file exists name

Returns 1 if file name exists and the current user has search privileges for the directories leading to it, 0 otherwise.

file extension name

Returns all of the characters in name after and including the last dot in the last element of name. If there is no dot in the last element of name then returns the empty string.

file isdirectory name

Returns 1 if file name is a directory, 0 otherwise.

file isfile name

Returns 1 if file name is a regular file, 0 otherwise.

file join name ?name ...?

Takes one or more file names and combines them, using the correct path separator for the current platform. If a particular name is relative, then it will be joined to the previous file name argument. Otherwise, any earlier arguments will be discarded, and joining will proceed from the current argument. For example,

file join a b /foo bar

returns /foo/bar.

Note that any of the names can contain separators, and that the result is always canonical for the current platform: / for Unix and Windows, and : for Macintosh.

file lstat name varName

Same as stat option (see below) except uses the lstat kernel call instead of stat. This means that if name refers to a symbolic link the information returned in varName 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 stat option.

file mkdir dir ?dir ...?

Creates each directory specified. For each pathname dir specified, this command will create all non-existing parent directories as well as dir 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.

file mtime name ?time?

Returns a decimal string giving the time at which file name was last modified. If time is specified, it is a modification time to set for the file (equivalent to Unix touch). 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.

file nativename name

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.

file owned name

Returns 1 if file name is owned by the current user, 0 otherwise.

file pathtype name

Returns one of absolute, relative, volumerelative. If name refers to a specific file on a specific volume, the path type will be absolute. If name refers to a file relative to the current working directory, then the path type will be relative. If name 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 volumerelative.

file readable name

Returns 1 if file name is readable by the current user, 0 otherwise.

file readlink name

Returns the value of the symbolic link given by name (i.e. the name of the file it points to). If name 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.

file rename ?-force? ?- -? source target

file rename ?-force? ?- -? source ?source ...? targetDir

The first form takes the file or directory specified by pathname source and renames it to target, moving the file if the pathname target specifies a name in a different directory. If target is an existing directory, then the second form is used. The second form moves each source file or directory into the directory targetDir. Existing files will not be overwritten unless the -force option is specified. 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 - - marks the end of switches; the argument following the - - will be treated as a source even if it starts with a -.

file rootname name

Returns all of the characters in name up to but not including the last ``.'' character in the last component of name. If the last component of name doesn't contain a dot, then returns name.

file size name

Returns a decimal string giving the size of file name in bytes. If the file doesn't exist or its size cannot be queried then an error is generated.

file split name

Returns a list whose elements are the path components in name. The first element of the list will have the same path type as name. 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

file split /foo/~bar/baz

returns / foo ./~bar baz to ensure that later commands that use the third component do not attempt to perform tilde substitution.

file stat name varName

Invokes the stat kernel call on name, and uses the variable given by varName to hold information returned from the kernel call. VarName is treated as an array variable, and the following elements of that variable are set: atime, ctime, dev, gid, ino, mode, mtime, nlink, size, type, uid. Each element except type is a decimal string with the value of the corresponding field from the stat return structure; see the manual entry for stat for details on the meanings of the values. The type element gives the type of the file in the same form returned by the command file type. This command returns an empty string.

file tail name

Returns all of the characters in name after the last directory separator. If name contains no separators then returns name.

file type name

Returns a string giving the type of file name, which will be one of file, directory, characterSpecial, blockSpecial, fifo, link, or socket.

file volume

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:/}).

file writable name

Returns 1 if file name is writable by the current user, 0 otherwise.

PORTABILITY ISSUES

Unix: These commands always operate using the real user and group identifiers, not the effective ones.

KEYWORDS

attributes, copy files, delete files, directory, file, move files, name, rename files, stat

Copyright © 1993 The Regents of the University of California.
Copyright © 1994-1996 Sun Microsystems, Inc.
Copyright © 1995-1997 Roger E. Critchlow Jr.

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