tk_getOpenFile(n) Tk Built-In Commands tk_getOpenFile(n)______________________________________________________________________________NAME
tk_getOpenFile, tk_getSaveFile - pop up a dialog box for the user to
select a file to open or save.
SYNOPSIStk_getOpenFile ?option value ...?
tk_getSaveFile ?option value ...?
_________________________________________________________________DESCRIPTION
The procedures tk_getOpenFile and tk_getSaveFile pop up a dialog box
for the user to select a file to open or save. The tk_getOpenFile com‐
mand is usually associated with the Open command in the File menu. Its
purpose is for the user to select an existing file only. If the user
enters a non-existent file, the dialog box gives the user an error
prompt and requires the user to give an alternative selection. If an
application allows the user to create new files, it should do so by
providing a separate New menu command.
The tk_getSaveFile command is usually associated with the Save as com‐
mand in the File menu. If the user enters a file that already exists,
the dialog box prompts the user for confirmation whether the existing
file should be overwritten or not.
The following option-value pairs are possible as command line arguments
to these two commands:
-confirmoverwrite boolean
Configures how the Save dialog reacts when the selected file
already exists, and saving would overwrite it. A true value
requests a confirmation dialog be presented to the user. A
false value requests that the overwrite take place without con‐
firmation. Default value is true.
-defaultextension extension
Specifies a string that will be appended to the filename if the
user enters a filename without an extension. The default value
is the empty string, which means no extension will be appended
to the filename in any case. This option is ignored on Mac OS X,
which does not require extensions to filenames, and the UNIX
implementation guesses reasonable values for this from the
-filetypes option when this is not supplied.
-filetypes filePatternList
If a File types listbox exists in the file dialog on the partic‐
ular platform, this option gives the filetypes in this listbox.
When the user choose a filetype in the listbox, only the files
of that type are listed. If this option is unspecified, or if it
is set to the empty list, or if the File types listbox is not
supported by the particular platform then all files are listed
regardless of their types. See the section SPECIFYING FILE PAT‐
TERNS below for a discussion on the contents of filePatternList.
-initialdir directory
Specifies that the files in directory should be displayed when
the dialog pops up. If this parameter is not specified, then the
files in the current working directory are displayed. If the
parameter specifies a relative path, the return value will con‐
vert the relative path to an absolute path.
-initialfile filename
Specifies a filename to be displayed in the dialog when it pops
up.
-message string
Specifies a message to include in the client area of the dialog.
This is only available on Mac OS X.
-multiple boolean
Allows the user to choose multiple files from the Open dialog.
-parent window
Makes window the logical parent of the file dialog. The file
dialog is displayed on top of its parent window. On Mac OS X,
this turns the file dialog into a sheet attached to the parent
window.
-title titleString
Specifies a string to display as the title of the dialog box. If
this option is not specified, then a default title is displayed.
-typevariable variableName
The global variable variableName is used to preselect which fil‐
ter is used from filterList when the dialog box is opened and is
updated when the dialog box is closed, to the last selected fil‐
ter. The variable is read once at the beginning to select the
appropriate filter. If the variable does not exist, or its value
does not match any filter typename, or is empty ({}), the dialog
box will revert to the default behavior of selecting the first
filter in the list. If the dialog is canceled, the variable is
not modified.
If the user selects a file, both tk_getOpenFile and tk_getSaveFile
return the full pathname of this file. If the user cancels the opera‐
tion, both commands return the empty string.
SPECIFYING FILE PATTERNS
The filePatternList value given by the -filetypes option is a list of
file patterns. Each file pattern is a list of the form
typeName {extension ?extension ...?} ?{macType ?macType ...?}?
typeName is the name of the file type described by this file pattern
and is the text string that appears in the File types listbox. exten‐
sion is a file extension for this file pattern. macType is a four-
character Macintosh file type. The list of macTypes is optional and may
be omitted for applications that do not need to execute on the Macin‐
tosh platform.
Several file patterns may have the same typeName, in which case they
refer to the same file type and share the same entry in the listbox.
When the user selects an entry in the listbox, all the files that match
at least one of the file patterns corresponding to that entry are
listed. Usually, each file pattern corresponds to a distinct type of
file. The use of more than one file pattern for one type of file is
only necessary on the Macintosh platform.
On the Macintosh platform, a file matches a file pattern if its name
matches at least one of the extension(s) AND it belongs to at least one
of the macType(s) of the file pattern. For example, the C Source Files
file pattern in the sample code matches with files that have a .c
extension AND belong to the macType TEXT. To use the OR rule instead,
you can use two file patterns, one with the extensions only and the
other with the macType only. The GIF Files file type in the sample code
matches files that either have a .gif extension OR belong to the mac‐
Type GIFF.
On the Unix and Windows platforms, a file matches a file pattern if its
name matches at least one of the extension(s) of the file pattern. The
macTypes are ignored.
SPECIFYING EXTENSIONS
On the Unix and Macintosh platforms, extensions are matched using glob-
style pattern matching. On the Windows platform, extensions are matched
by the underlying operating system. The types of possible extensions
are:
(1) the special extension “*” matches any file;
(2) the special extension matches any files that do not have an
extension (i.e., the filename contains no full stop character);
(3) any character string that does not contain any wild card
characters (* and ?).
Due to the different pattern matching rules on the various platforms,
to ensure portability, wild card characters are not allowed in the
extensions, except as in the special extension “*”. Extensions without
a full stop character (e.g. “~”) are allowed but may not work on all
platforms.
EXAMPLE
set types {
{{Text Files} {.txt} }
{{TCL Scripts} {.tcl} }
{{C Source Files} {.c} TEXT}
{{GIF Files} {.gif} }
{{GIF Files} {} GIFF}
{{All Files} * }
}
set filename [tk_getOpenFile -filetypes $types]
if {$filename != ""} {
# Open the file ...
}
SEE ALSO
tk_chooseDirectory
KEYWORDS
file selection dialog
Tk 4.2 tk_getOpenFile(n)