dialogs4docmetadata

First attempt to use Bash Dialog for user interaction. Guides user collecting metadata for scanning a documents.

Links

• linuxcommand.org: dialog
• Manpage dialog
• Linux Gazette: Designing Simple front ends with dialog/Xdialog
• linux-community: mehr Komfort mit Dialog
• Dialog buildlist Beispiel
• Dialog Script-Beispiele
• UbuntuUsers: Dialog Bash GUI
• UbuntuUsers: Dialog-Optionen
• Rheinwerk: Dialog
• Wikipedia: Zeichenorientierte Benutzerschnittstelle

Exit-Codes

Button / Taste	Exit-Code ($?)	RETURN-Value
OK	0	value
Yes	0	-
No	1	-
Cancel	1	-
<Ctrl> + C	1	-
Help	2	HELP value
Extra	3	value
<ESC>	255	-

--exit-label string
--default-button string --> ok, yes, cancel, no, help, extra
--extra-button
--extra-label string
--help-button
--help-label string
--no-cancel
--no-label string
--no-ok
--ok-label
--yes-label

Umlekung der File-Deskriptoren

Alternative 1: exec

# create a backup copy of file descriptor 1 (STDOUT) on descriptor 3
#exec 3>&1

# Generate the dialog box
ANSWER=$($DIALOG ... \
    2>&1 1>&3 )

# Get the exit status
DIALOG_EXIT_STATUS=$?

# Close file descriptor 3
exec 3>&-

echo "${ANSWER}"

Alternative 2: redirection

# Generate the dialog box
ANSWER=$($DIALOG ... \
    3>&1 1>&2 2>&3 )

# Get the exit status
DIALOG_EXIT_STATUS=$?

echo "${ANSWER}"