Dialog
is a program that will let you to present a variety of questions or
display messages using dialog boxes from a shell script.
These types of dialog boxes are implemented
(though not all are necessarily compiled into dialog):
calendar,
checklist,
form,
fselect,
gauge,
infobox,
inputbox,
inputmenu,
menu,
msgbox (message),
password,
radiolist,
tailbox,
tailboxbg,
textbox,
timebox, and
yesno (yes/no).
You can put more than one dialog box into a script:
-
Use the --and-widget token to force Dialog to proceed to the next
dialog unless you have pressed ESC to cancel, or
-
Simply add the tokens for the next dialog box, making a chain.
Dialog stops chaining when the return code from a dialog is nonzero,
e.g., Cancel or No (see DIAGNOSTICS).
Some widgets, e.g., checklist, will write text to dialog's output.
Normally that is the standard error, but there are options for
changing this: --output-fd, --stderr and --stdout.
No text is written if the Cancel button (or ESC) is pressed;
dialog exits immediately in that case.
OPTIONS
All options begin with "--".
A "--" by itself is used as an escape,
i.e., the next token on the command-line is not treated as an option.
dialog --title -- --Not an option
The "--file" option tells dialog to read parameters from
the file named as its value.
dialog --file parameterfile
Common Options
--aspect ratio
This gives you some control over the box dimensions when using auto
sizing (specifying 0 for height and width).
It represents width / height.
The default is 9, which means 9 characters wide to every 1 line high.
--backtitle backtitle
Specifies a
backtitle
string to be displayed on the backdrop, at the top of the screen.
--beep
Sound the audible alarm
each time the screen is refreshed.
--beep-after
Beep if input is interrupted, e.g., by a control/C.
--begin
y x
Specify the position of the upper left corner of a dialog box on the screen.
--cancel-label string
Override the label used for "Cancel" buttons.
--clear
The screen will be cleared on exit.
This may be used alone, without other options.
--colors
Interpret embedded "\Z" sequences in the dialog text
by the following character,
which tells dialog
to set colors or video attributes:
0 through 7 are the ANSI used in curses:
black,
red,
green,
yellow,
blue,
magenta,
cyan and
white respectively.
Bold is set by 'b', reset by 'B'.
Reverse is set by 'r', reset by 'R'.
Underline is set by 'u', reset by 'U'.
The settings are cumulative, e.g., "\Zb\Z1" makes the following text
bright red.
Restore normal settings with "\Zn".
--cr-wrap
Interpret embedded newlines in the dialog text as a newline on the screen.
Otherwise, dialog
will only wrap lines where needed to fit inside the text box.
Even though you can control line breaks with this,
dialog will still wrap any lines that are too long for the width of the box.
Without cr-wrap, the layout of your text may be formatted to look nice
in the source code of your script without affecting the way it will
look in the dialog.
--create-rc file
When
dialog
supports run-time configuration,
this can be used to dump a sample configuration file to the file specified
by
file.
--defaultno
Make the default value of the
yes/no
box a
No.
Likewise, make the default button of widgets that provide "OK" and "Cancel"
a Cancel.
If --nocancel was given that option overrides this,
making the default button always "Yes" (internally the same as "OK").
--default-item string
Set the default item in a checklist, form or menu box.
Normally the first item in the box is the default.
--exit-label string
Override the label used for "EXIT" buttons.
--extra-button
Show an extra button, between "OK" and "Cancel" buttons.
--extra-label
string
Override the label used for "Extra" buttons.
Note: for inputmenu widgets, this defaults to "Rename".
--help
Prints the help message to dialog
's output.
The help message is printed if no options are given.
--help-button
Show a help-button after "OK" and "Cancel" buttons,
i.e., in checklist, radiolist and menu boxes.
If --item-help
is also given, on exit
the return status will be the same as for the "OK" button,
and the item-help text will be written to dialog's output after the token "HELP".
Otherwise, the return status will indicate that the Help button was pressed,
and no message printed.
--help-label string
Override the label used for "Help" buttons.
--help-status
If the help-button is selected,
writes the checklist, radiolist or form information
after the item-help "HELP" information.
This can be used to reconstruct the state of a checklist after processing
the help request.
--ignore
Ignore options that dialog
does not recognize.
Some well-known ones such as "--icon" are ignored anyway,
but this is a better choice for compatibility with other implementations.
--input-fd fd
Read keyboard input from the given file descriptor.
Most
dialog scripts read from the standard input,
but the gauge widget reads a pipe (which is always standard input).
Some configurations do not work properly when
dialog tries to reopen the terminal.
Use this option (with appropriate juggling of file-descriptors)
if your script must work in that type of environment.
--insecure
Makes the password widget friendlier but less secure,
by echoing asterisks for each character.
--item-help
Interpret the tags data for checklist, radiolist and menu boxes
adding a column which is displayed in the bottom line of the
screen, for the currently selected item.
--keep-window
Do not remove/repaint the window on exit.
This is useful for keeping the window contents visible when several
widgets are run in the same process.
Note that curses will clear the screen when starting a new process.
--max-input
size
Limit input strings to the given size.
If not specified, the limit is 2048.
--no-cancel
--nocancel
Suppress the "Cancel" button in checklist, inputbox and menu box modes.
A script can still test if the user pressed the ESC key to cancel to quit.
--no-collapse
Normally dialog
converts tabs to spaces and reduces multiple
spaces to a single space for text which is displayed in a message boxes, etc.
Use this option to disable that feature.
Note that dialog will still wrap text, subject to the --cr-wrap
option.
--no-kill
Tells
dialog
to put the
tailboxbg
box in the background,
printing its process id to dialog's output.
SIGHUP is disabled for the background process.
--no-label string
Override the label used for "No" buttons.
--no-shadow
Suppress shadows that would be drawn to the right and bottom of each dialog box.
--ok-label
string
Override the label used for "OK" buttons.
--output-fd fd
Direct output to the given file descriptor.
Most
dialog scripts write to the standard error,
but error messages may also be written there, depending on your script.
--print-maxsize
Print the maximum size of dialog boxes, i.e., the screen size,
to dialog
's output.
This may be used alone, without other options.
--print-size
Prints the size of each dialog box to dialog
's output.
--print-version
Prints dialog
's version to dialog's output.
This may be used alone, without other options.
--separate-output
For checklist widgets, output result one line at a time, with no quoting.
This facilitates parsing by another program.
--separator
string
--separate-widget string
Specify a string that will separate the output on
dialog's output from
each widget.
This is used to simplify parsing the result of a dialog with several widgets.
If this option is not given,
the default separator string is a tab character.
--shadow
Draw a shadow to the right and bottom of each dialog box.
--size-err
Check the resulting size of a dialog box before trying to use it,
printing the resulting size if it is larger than the screen.
(This option is obsolete, since all new-window calls are checked).
--sleep
secs
Sleep (delay) for the given number of seconds after processing a dialog box.
--stderr
Direct output to the standard error.
This is the default, since curses normally writes screen updates to
the standard output.
--stdout
Direct output to the standard output.
This option is provided for compatibility with Xdialog,
however using it in portable scripts is not recommended,
since curses normally writes its screen updates to the standard output.
If you use this option, dialog
attempts to reopen the terminal
so it can write to the display.
Depending on the platform and your environment, that may fail.
--tab-correct
Convert each tab character to one or more spaces.
Otherwise, tabs are rendered according to the curses library's interpretation.
--tab-len
n
Specify the number of spaces that a tab character occupies if the
"
--tab-correct"
option is given.
The default is 8.
--timeout secs
Timeout (exit with error code)
if no user response within the given number of seconds.
--title title
Specifies a
title
string to be displayed at the top of the dialog box.
--trim
eliminate leading blanks,
trim literal newlines and repeated blanks from message text.
--version
Same as "--print-version
".
--yes-label string
Override the label used for "Yes" buttons.
Box Options
All dialog boxes have at least three parameters:
text
the caption or contents of the box.
height
the height of the dialog box.
width
the width of the dialog box.
Other parameters depend on the box type.
--calendar text height width day month year
A
calendar box displays
month, day and year in separately adjustable windows.
If the values for day, month or year are missing or negative,
the current date's corresponding values are used.
You can increment or decrement any of those using the
left-, up-, right- and down-arrows.
Use vi-style h, j, k and l for moving around the array of days in a month.
Use tab or backtab to move between windows.
If the year is given as zero, the current date is used as an initial value.
On exit, the date is printed in the form day/month/year.
--checklist text height width list-height [ tag item status ] ...
A
checklist
box is similar to a
menu
box; there are
multiple entries presented in the form of a menu.
Instead of choosing
one entry among the entries, each entry can be turned on or off by the user.
The initial on/off state of each entry is specified by
status.
On exit, a list of the tag
strings of those entries that are turned on
will be printed on dialog's output.
If the --separate-output option is not given,
the strings will be quoted to make it simple for scripts to separate them.
--form text height width formheight [ label y x item y x flen ilen ] ...
The form dialog displays a form consisting of labels and fields,
which are positioned on a scrollable window by coordinates given in the script.
The field length flen and input-length ilen tell how long
the field can be.
The former defines the length shown for a selected field,
while the latter defines the permissible length of the data entered in the
field.
If flen is zero, the corresponding field cannot be altered.
If ilen is zero, it is set to flen.
Use up/down arrows (or control/N, control/P) to move between fields.
Use tab to move between windows.
On exit, the contents of the form-fields are written to dialog's output,
each field separated by a newline.
Input-only fields (flen is zero) are not written out.
--fselect filepath height width
The file-selection dialog displays a text-entry window in which you can type
a filename (or directory), and above that two windows with directory
names and filenames.
Here
filepath
can be a filepath in which case the file and directory windows
will display the contents of the path and the text-entry window will contain
the preselected filename.
Use tab or arrow keys to move between the windows.
Within the directory or filename windows, use the up/down arrow keys
to scroll the current selection.
Use the space-bar to copy the current selection into the text-entry
window.
Typing any printable characters switches focus to the text-entry window,
entering that character as well as scrolling the directory and filename
windows to the closest match.
Use a carriage return or the "OK" button to accept the current value
in the text-entry window and exit.
On exit, the contents of the text-entry window are written to dialog's output.
--gauge text height width [percent]
A
gauge
box displays a meter along the bottom of the box.
The meter indicates the percentage.
New percentages are read from
standard input, one integer per line.
The meter is updated
to reflect each new percentage.
If the standard input reads the string "XXX",
then subsequent lines up to another "XXX" are used for a new prompt.
The gauge exits when EOF is reached on the standard input.
The percent value denotes the initial percentage shown in the meter.
If not specified, it is zero.
On exit, no text is written to dialog's output.
The widget accepts no input, so the exit status is always OK.
--infobox text height width
An
info box is basically a message box.
However, in this case, dialog
will exit immediately after displaying the message to the user.
The screen is not cleared when dialog
exits, so that the message will remain on the screen until the calling
shell script clears it later.
This is useful when you want to inform
the user that some operations are carrying on that may require some
time to finish.
On exit, no text is written to dialog's output.
Only an "OK" button is provided for input,
but an ESC exit status may be returned.
--inputbox text height width [init]
An
input
box is useful when you want to ask questions that
require the user to input a string as the answer.
If init is supplied
it is used to initialize the input string.
When entering the string,
the backspace, delete and cursor keys
can be used to correct typing errors.
If the input string is longer than
can fit in the dialog box, the input field will be scrolled.
On exit, the input string will be printed on dialog's output.
--inputmenu text height width menu-height [ tag item ] ...
An
inputmenu box is very similar to an ordinary menu box.
There are only a few differences between them:
1.
The entries are not automatically centered but left adjusted.
2.
An extra button (called Rename) is implied to rename
the current item when it is pressed.
3.
It is possible to rename the current entry by pressing the
Rename
button.
Then dialog will write the following on dialog's output.
RENAMED <tag> <item>
--menu text height width menu-height [ tag item ] ...
As its name suggests, a
menu
box is a dialog box that can be used to present a list of choices in
the form of a menu for the user to choose.
Choices are displayed in the order given.
Each menu entry consists of a tag string and an item string.
The tag
gives the entry a name to distinguish it from the other entries in the
menu.
The item is a short description of the option that the entry represents.
The user can move between the menu entries by pressing the
cursor keys, the first letter of the tag
as a hot-key, or the number keys
1-9. There are
menu-height
entries displayed in the menu at one time, but the menu will be
scrolled if there are more entries than that.
On exit the tag
of the chosen menu entry will be printed on dialog's output.
If the --help-button option is given, the corresponding help
text will be printed if the user selects the help button.
--msgbox text height width
A
message box is very similar to a yes/no box.
The only difference between a message box and a yes/no
box is that a message box has only a single OK button.
You can use this dialog box to display any message you like.
After reading the message, the user can press the ENTER key so that
dialog will exit and the calling shell script can continue its operation.
On exit, no text is written to dialog's output.
Only an "OK" button is provided for input,
but an ESC exit status may be returned.
--passwordbox text height width [init]
A
password box is similar to an input box,
except that the text the user enters is not displayed.
This is useful when prompting for passwords or other
sensitive information.
Be aware that if anything is passed in "init", it
will be visible in the system's process table to casual snoopers.
Also, it
is very confusing to the user to provide them with a default password they
cannot see.
For these reasons, using "init" is highly discouraged.
See "--insecure" if you do not care about your password.
On exit, the input string will be printed on dialog's output.
--radiolist text height width list-height [ tag item status ] ...
A
radiolist
box is similar to a
menu
box.
The only difference is
that you can indicate which entry is currently selected, by setting its
status to on.
On exit, the name of the selected item is written to dialog's output.
--tailbox file height width
Display text from a file in a dialog box, as in a "tail -f" command.
Scroll left/right using vi-style 'h' and 'l', or arrow-keys.
A '0' resets the scrolling.
On exit, no text is written to dialog
's output.
Only an "OK" button is provided for input,
but an ESC exit status may be returned.
--tailboxbg file height width
Display text from a file in a dialog box as a background task,
as in a "tail -f &" command.
Scroll left/right using vi-style 'h' and 'l', or arrow-keys.
A '0' resets the scrolling.
Dialog treats the background task specially if there are other
widgets (--and-widget
) on the screen concurrently.
Until those widgets are closed (e.g., an "OK"),
dialog will perform all of the tailboxbg widgets in the same process,
polling for updates.
You may use a tab to traverse between the widgets on the screen,
and close them individually, e.g., by pressing ENTER.
Once the non-tailboxbg widgets are closed, dialog forks a copy of itself
into the background, and prints its process id if the --no-kill option
is given.
On exit, no text is written to dialog's output.
Only an "EXIT" button is provided for input,
but an ESC exit status may be returned.
NOTE:
Older versions of dialog forked immediately and attempted to
update the screen individually.
Besides being bad for performance,
it was unworkable.
Some older scripts may not work properly with the polled scheme.
--textbox file height width
A
text
box lets you display the contents of a text file in a dialog box.
It is like a simple text file viewer.
The user can move through the file by using the
cursor, PGUP/PGDN
and HOME/END keys available on most keyboards.
If the lines are too long to be displayed in the box,
the LEFT/RIGHT
keys can be used to scroll the text region horizontally.
You may also use vi-style keys h, j, k, l in place of the cursor keys,
and B or N in place of the pageup/pagedown keys.
Scroll up/down using vi-style 'k' and 'j', or arrow-keys.
Scroll left/right using vi-style 'h' and 'l', or arrow-keys.
A '0' resets the left/right scrolling.
For more convenience,
vi-style forward and backward searching functions are also provided.
On exit, no text is written to dialog's output.
Only an "EXIT" button is provided for input,
but an ESC exit status may be returned.
--timebox text height [width hour minute second]
A dialog is displayed which allows you to select hour, minute and second.
If the values for hour, minute or second are missing or negative,
the current date's corresponding values are used.
You can increment or decrement any of those using the
left-, up-, right- and down-arrows.
Use tab or backtab to move between windows.
On exit, the result is printed in the form hour:minute:second.
--yesno text height width
A
yes/no dialog box of
size height rows by width columns will be displayed.
The string specified by
text
is displayed inside the dialog box.
If this string is too long to fit
in one line, it will be automatically divided into multiple lines at
appropriate places.
The
text
string can also contain the sub-string
"\n"
or newline characters
`\n'
to control line breaking explicitly.
This dialog box is useful for
asking questions that require the user to answer either yes or no.
The dialog box has a
Yes
button and a
No
button, in which the user can switch between by pressing the
TAB key.
On exit, no text is written to dialog's output.
In addition to the "Yes" and "No" exit codes (see DIAGNOSTICS)
an ESC exit status may be returned.
The codes used for "Yes" and "No" match those used for "OK" and "Cancel",
internally no distinction is made.
RUN-TIME CONFIGURATION
1.
Create a sample configuration file by typing:
"dialog --create-rc <file>"
2.
At start,
dialog
determines the settings to use as follows:
a)
if environment variable
DIALOGRC
is set, its value determines the name of the configuration file.
b)
if the file in (a) is not found, use the file
$HOME/.dialogrc
as the configuration file.
c)
if the file in (b) is not found, try using the GLOBALRC file determined at
compile-time, i.e., /etc/dialogrc.
d)
if the file in (c) is not found, use compiled in defaults.
3.
Edit the sample configuration file and copy it to some place that
dialog
can find, as stated in step 2 above.
ENVIRONMENT
DIALOGRC
Define this variable if you want to specify the name of the configuration file
to use.
DIALOG_CANCEL
DIALOG_ERROR
DIALOG_ESC
DIALOG_EXTRA
DIALOG_HELP
DIALOG_OK
Define any of these variables to change the exit code on
Cancel (1),
error (-1),
ESC (255),
Extra (3),
Help (2),
or OK (0).
Normally shell scripts cannot distinguish between -1 and 255.
DIALOG_TTY
Set this variable to "1" to provide compatibility with older versions
of dialog which assumed that if the script redirects the standard output,
that the "--stdout" option was given.
FILES
$HOME/.dialogrc
default configuration file
EXAMPLES
The dialog sources contain several samples
of how to use the different box options and how they look.
Just take a look into the directory samples/ of the source.
DIAGNOSTICS
Exit status is subject to being overridden by environment variables.
Normally they are:
0
if
dialog is exited by pressing the Yes or OK
button.
1
if the
No or Cancel
button is pressed.
2
if the
Help
button is pressed.
3
if the
Extra
button is pressed.
-1
if errors occur inside dialog
or dialog is exited by pressing the ESC key.
