tk_getOpenFile(n) Tk (4.2) tk_getOpenFile(n)
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NAME
tk_getOpenFile, tk_getSaveFile - pop up a dialog box for the
user to select a file to open or save.
SYNOPSIS
tk_getOpenFile ?option value ...?
tk_getSaveFile ?option value ...?
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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 command 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 an 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 command 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:
-defaultextension extension
Specifies a string that will be appended to the
filename if the user enters a filename without an
extension. The defaut value is the empty string, which
means no extension will be appended to the filename in
any case. This option is ignored on the Macintosh
platform, which does not require extensions to
filenames.
-filetypes filePatternList
If a File types listbox exists in the file dialog on
the particular 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 PATTERNS below for a discussion on the
contents of filePatternList.
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tk_getOpenFile(n) Tk (4.2) tk_getOpenFile(n)-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 convert the
relative path to an absolute path. This option may not
always work on the Macintosh. This is not a bug.
Rather, the General Controls control panel on the Mac
allows the end user to override the application default
directory.
-initialfile filename
Specifies a filename to be displayed in the dialog when
it pops up. This option is ignored by the
tk_getOpenFile command.
-parent window
Makes window the logical parent of the file dialog. The
file dialog is displayed on top of its 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. This option is ignored on
the Macintosh platform.
If the user selects a file, both tk_getOpenFile and
tk_getSaveFile return the full pathname of this file. If the
user cancels the operation, 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. extension 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 Macintosh
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 patterns for one type of file
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tk_getOpenFile(n) Tk (4.2) tk_getOpenFile(n)
is necessary on the Macintosh platform only.
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 macType GIFF.
On the Unix and Windows platforms, a file matches a file
pattern if its name matches at 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 platforms,
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 ...
}
KEYWORDS
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tk_getOpenFile(n) Tk (4.2) tk_getOpenFile(n)
file selection dialog
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