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Displays a dialog prompting the user for a filename.



prompt-for-file message &key pathname ok-check filter filters if-exists if-does-not-exist file-package-is-directory operation owner pane-args popup-args continuation => filename , successp , filter-name


A string or nil.


A pathname designator or nil.


A function or nil.


A string or nil.


A property list.


One of :ok or :prompt.


One of :ok, :prompt or :error.


A generalized boolean.


One of :open or :save.


An owner window.


A function or nil.



A pathname or nil.


A boolean.


A string.


The function prompt-for-file prompts the user for a file using a dialog box.

pathname , if non-nil, is a pathname designator providing a default filename for the dialog.

ok-check , if non-nil, should be a function which takes a pathname designator argument and returns a true value if the pathname is valid.

filter specifies the initial filter expression. The default value is "*.*". An example filter expression with multiple filters is "*.LISP;*.LSP".

filter is used on all platforms. However on Motif, if filter contains multiple file types, only the first of these is used.

On Cocoa prompt-for-file supports the selection of application bundles as files if they match the filter. For example, they will match if the filter expression contains *.app or *.*.

filters is a property list of filter names and filter expressions, presenting filters which the user can select in the dialog. If the filter argument is not one of the expressions in filters , an extra filter called "Files" is added for this expression.

On Microsoft Windows the default value of filters is:

("Lisp Source Files" "*.LISP;*.LSP"
 "Lisp Fasls" "*.OFASL"
 "Text Documents" "*.DOC;*.TXT"
 "Image Files" "*.BMP;*.DIB;*.ICO;*.CUR"
 "All Files" "*.*")

The "Lisp Fasls" extension may vary depending on the implementation.

On Cocoa and GTK+ the default value of filters is:

("Lisp Source Files" "*.lisp;*.lsp"
 "Text Documents" "*.txt;*.text"
 "All Files" "*.*")

filters is ignored on Motif.

When if-exists is :ok, an existing file can be returned. Otherwise the user is prompted about whether the file can be overwritten. The default for if-exists is :ok when operation is :open and :prompt when operation is :save.

When if-does-not-exist is :ok, a non-existent file can be chosen. When it is :prompt, the user is prompted if a non-existent file is chosen. When it is :error, the user cannot choose a non-existent file. The default for if-does-not-exist is :prompt if operation is :open and :ok if operation is :save.

operation chooses the style of dialog used, in LispWorks for Windows only. The default value is :open.

owner , if non-nil, specifies an owner window for the dialog. See Dialogs: Prompting for Input for details.

If continuation is non-nil, then it must be a function with a lambda list that accepts three arguments. The continuation function is called with the values that would normally be returned by prompt-for-file. On Cocoa, passing continuation causes the dialog to be made as a window-modal sheet and prompt-for-file returns immediately, leaving the dialog on the screen. The with-dialog-results macro provides a convenient way to create a continuation function.

On Motif, the prompt itself is created by passing an appropriate pane to popup-confirmer. Arguments can be passed to the make-instance of the pane and the call to popup-confirmer using pane-args and popup-args respectively. Currently, the pane used to create the file prompter is internal to the CAPI. pane-args and popup-args are ignored on Microsoft Windows.

filename is the full pathname of the file selected, or nil if the dialog was cancelled.

successp is a flag which is nil if the dialog was cancelled, and t otherwise.

On Microsoft Windows prompt-for-file returns a third value: filter-name is the name of the filter that was selected in the dialog.

file-package-is-directory controls how to treat file packages on Cocoa. By default it is nil, which means that a file package is treated as file. If file-package-is-directory is non-nil, the a file package is treated as a directory. file-package-is-directory corresponds to the treatsFilePackagesAsDirectories method of NSSavePanel in Cocoa. It has no effect on other platforms.

(capi:prompt-for-file "Enter a filename:")
(capi:prompt-for-file "Enter a filename:"
                      :pathname "/usr/bin/cal")
(capi:prompt-for-file "Enter a filename:"
                      :ok-check 'probe-file)
See also

Dialogs: Prompting for Input

CAPI User Guide and Reference Manual (Unix version) - 25 Feb 2015