___________________________
tk_getOpenFile, tk_getSaveFile − pop up a dialog box for the user to select a file to open or save.
tk_getOpenFile
?option value ...?
tk_getSaveFile ?option value ...?
___________________________
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 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 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:
−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 confirmation. 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 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.
−initialdir directory
Specifies that the files in directory should be displayed when the dialog pops up. If this parameter is not specified, the initial directory defaults to the current working directory on non-Windows systems and on Windows systems prior to Vista. On Vista and later systems, the initial directory defaults to the last user-selected directory for the application. If the parameter specifies a relative path, the return value will convert 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 filter is used from filterList when the dialog box is opened and is updated when the dialog box is closed, to the last selected filter. 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 operation, both commands return the empty string.
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 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 macType 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.
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.
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
ne ""} {
# Open the file ...
}
tk_chooseDirectory
file selection dialog
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.