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Help function of "dialog"

Link to this post 28 Nov 11

Hi all,

I'm currently writing some bash scripts using the "dialog" functionality to enhance the user experience on the command line.

All is going well, but there is one problem I cannot sort out and little info is found via Google, that is, the help system of dialog. There are options to show a help button and when the user selects it, the corresponding help text appears.
I can get the button to shop up, but there is no documentation on how to show the corresponding help text into a box. Dialog just quits with "HELP:<helpname>".

Does anyone here on the forums have any usable knowledge about the help functionality of dialog and is willing to help me out?

Thanks in advance and should you need more information, please ask, so I can supply it.

Link to this post 28 Nov 11

Hmm, I haven't thought about that strategy yet. Though it is a bit cumbersome, especially when handling multiple actions and various dialog boxes. I would have to think about a good strategy for that.

Another question, if I read the help correctly, it should be possible to keep the originating window and place the help window on top of that. Do you have any idea to accomplish this?

Thanks already for your help!

Link to this post 29 Nov 11

That's possible, I'm only pasting the part of what's relevant, since it's a huge script by now :)

#!/bin/bash
escaper()
{
action=$?
if [ $action = 1 -o $action = 255 ];
then
dialog --title "$title" --yesno "\nAre you sure you want to quit?" 7 35
sure=$?
if [ $sure = 0 ];
then
clear
exit
fi
fi
}
genhour()
{
genhour=9
hour=$RANDOM
let "hour %= $genhour"
}
genminute()
{
genminute=59
minute=$RANDOM
let "minute %= $genminute"
}
pid=$(echo $$)
if [ -z $1 ];
then
genhour
genminute
dialog --backtitle "$backtitle" --title "$title" --keep-window --form "\nYour Backup Account Details\n" 20 60 0 \
"Username....:" 1 1 "" 1 15 14 0 \
"Password....:" 2 1 "" 2 15 14 0 \
"Server......:" 3 1 "" 3 15 30 0 \
"Backup root.:" 4 1 "/" 4 15 30 0 \
"Weeks.......:" 5 1 "0" 5 15 2 0 \
"Months......:" 6 1 "0" 6 15 2 0 \
"MySQL dumps.:" 7 1 "$mysqldumps" 7 15 1 0 \
"SQL Dir.....:" 8 1 "/var/sqlbackups/" 8 15 30 0 \
"Cron (HH)...:" 9 1 "$hour" 9 15 2 0 \
"Cron (MM)...:" 10 1 "$minute" 10 15 2 0 \
"Logging.....:" 11 1 "Y" 11 15 1 0 \
"Email log...:" 12 1 "N" 12 15 1 0 \
"Emailaddress:" 13 1 "" 13 15 30 0 2> /tmp/$pid-options
escaper
choice=$?
array=( `cat /tmp/$pid-options `)
if [ -f /tmp/$pid-options ];
then
rm /tmp/$pid-options > /dev/null 2> /dev/null
fi
while ! [ ${#array[@]} = 13 ]
do
dialog --backtitle "$backtitle" --title "$title" --msgbox "\nNot all fields are populated!\n\nPlease make sure you fill in all the fields." 10 50; clear
genhour
genminute
dialog --backtitle "$backtitle" --title "$title" --keep-window --form "\nYour Backup Account Details\n" 20 60 0 \
"Username....:" 1 1 "" 1 15 14 0 \
"Password....:" 2 1 "" 2 15 14 0 \
"Server......:" 3 1 "" 3 15 30 0 \
"Backup root.:" 4 1 "$defaultbackuppath" 4 15 30 0 \
"Weeks.......:" 5 1 "0" 5 15 2 0 \
"Months......:" 6 1 "0" 6 15 2 0 \
"MySQL dumps.:" 7 1 "$mysqldumps" 7 15 1 0 \
"SQL Dir.....:" 8 1 "/var/sqlbackups/" 8 15 30 0 \
"Cron (HH)...:" 9 1 "$hour" 9 15 2 0 \
"Cron (MM)...:" 10 1 "$minute" 10 15 2 0 \
"Logging.....:" 11 1 "Y" 11 15 1 0 \
"Email log...:" 12 1 "N" 12 15 1 0 \
"Emailaddress:" 13 1 "" 13 15 30 0 2> /tmp/$pid-options
escaper
choice=$?
array=( `cat /tmp/$pid-options `)
if [ -f /tmp/$pid-options ];
then
rm /tmp/$pid-options > /dev/null 2> /dev/null
fi
done
fi

As you can see, it's showing a message if the array is not completely filled. I want that window on top of the original box, so if a user selects OK, it returns to the original window, keeping the fields with their input.

As stated before, it's not the complete code, but enough to run :). Should you need more, let me know. And indeed, the manpage on dialog is very limited...

Link to this post 30 Nov 11

Before getting into your problem, I'll make a couple of suggestions.

Since you are using bash ((#!/bin/bash):
1 - Use [[ (builtin) instead of [ (external test/[ command). [[ is safer,faster and has more options than test/[
2 - Don't use `` for commands, as it is deprecated. Use $() instead (it's easier to nest commands, better readability, you can use "",etc)
3 - Try not to insert external commands into variables ( array=( ` cat /tmp/$pid-option `) ). Better use something like:

  while read -r line
do
echo "$line"
done < "$file"

4 - "pid=$(echo $$)" ?? Why not just "pid=$$"? ( This could go in the point 3 )

Now, to your problem:

You have the options that the user chose in the /tmp/$pid-options file (or in the array variable) , why don't you use that info to fill the blanks on the call to the dialog? I mean, if your user, for example, just introduced the "Username" field that data can be used to fill the first spot in your dialog:


"Username....:" 1 1 "${array[0]}" 1 15 14 0

Gosshhh I love scripting :D

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