Ubuntu – How to easily create a GUI dialog with a bash script

bashcommand linescriptsyadzenity

I need to present some text along with the items(about 15 values) for each of two Bash list(file) records. On the same screen I need to present a three way selection, (buttons, scrolled selection window, etc.).

I'm an Ubuntu(11.04) scripting noob just beginning to use Zenity in scripts. My friends suggested YAD.

Can I do all of that in YAD or use some other easy GUI tool unknown to us?

Best Answer

Here's a very minimal implementation in Yad.

A textfile named 'mylist' in the same directory as the script contains "1 2 3 4 5 6 7 8 9 10". A space character is the default delimeter for input into lists.

The example script is:

#/bin/bash
thelist=$(<mylist)
thechoice=$(yad --title="Choose a value" --width=200 --height=200 --list --column="Values" --separator="" $thelist)
exit $(yad --title="You chose..." --text=$thechoice)

That's it. Scrolling the list is handled automatically. The --separator="" is to supress Yad's default of appending a pipe character ("|") to the output.

When you read the man page, you will see that you have a large array of possibilites. You can add buttons, icons, radio buttons, etc. You can create tabbed dialogs by using Yad's Notebook feature to embed dialogs within other dialogs as plugins.

There's a long example at PCLinusOS mag and some interesting shorter examples at the Yad site.

YAD (Yet Another Dialog) is the best method

YAD is a fork of Zenity and provides advanced controls over buttons, lists and GTK interfaces. For example when entering a file name in this answer YAD easily provides us the regular GUI system interface:

Sample main dialog window

The main window hides the record number column which you can reveal for debugging purposes:

Sample Insert / Edit window

The same window is used for inserting records before an existing record or editing an existing record:

Notice the "File name" field. When you enter it the file selection dialog box in the first section appears.

The bash code

Here is the bash code to make the sample YAD insert/edit/delete records template. Note extra coding is still needed to read in the file and add processing logic for the "Run" command. Additional coding is probably required to support file names with embedded spaces but that hasn't been tested yet.

#!/bin/bash

# NAME: websync
# PATH: $HOME/bin
# DESC: Provide list of files and corresponding website addresses.

# DATE: Mar 25, 2017.

# NOTE: Uses yad which is fork of zenity which is GUI fork of dialog.

# TODO: Add local file date modified. Add Answer last revision date.
#       Add question title.
#       Add file word count, or size, or ignore as irrelevant?
#   Add answer word count if file word count is displayed.
#       Add answer up votes.
#   Scan directory to add all files. ("Populate" button)
#   Initialize $ListArr[@] < /home/$USER/bin/.websync
#   Use "|" as ListArr delimeter or (double quotes?) for file names with spaces

# Must have the yad package.
command -v yad >/dev/null 2>&1 || { echo >&2 "yad package required but it is not installed.  Aborting."; exit 99; }

# Must have the zenity package.
command -v zenity >/dev/null 2>&1 || { echo >&2 "yad package required but it is not installed.  Aborting."; exit 99; }

RenumberListArr () {
# This is called after inserting or deleting records.
# Record numbers may not be sequential because user can sort on any column
# Record nubmers must be unique as they are used to find the correct record in ListArr array.
# Matching on "file name" or any other field is impossible because there may be duplicate names.

# Define variables for easy reading and fewer code line changes when expanding
RecArrCnt=5
ListArrCnt=${#ListArr[@]}

i=1 # First element (0) is "false", followed by record number element (1)
j=1 # Record numbers start at 1

while [ $i -lt $ListArrCnt ] ; do
    ListArr[$i]=$j
    j=$(($j + 1))
    i=$(($i + $RecArrCnt))
# echo "Renumber i: $i j: $j"
done

}

OLDIFS="$IFS"
IFS="|"
ListArr=()

# TODO: Replace this section with IFS=' ' read -ra CfgArr < /home/$USER/bin/.websync

ListArr=("${ListArr[@]}" false "1" "/usr/local/bin/display-auto-brightness" "Different")
Modified=$(stat "/usr/local/bin/display-auto-brightness" | grep "Modify:"| cut -f2 -d" ")
echo "Modified: $Modified" # File modified date is a future list array new field
ListArr=("${ListArr[@]}" "http://askubuntu.com/questions/894460/automatically-adjust-display-brightness-based-on-sunrise-and-sunset/894470#894470")
ListArr=("${ListArr[@]}" false "2" "/usr/local/bin/sun-hours" "Matches")
ListArr=("${ListArr[@]}" "http://askubuntu.com/questions/894460/automatically-adjust-display-brightness-based-on-sunrise-and-sunset/894470#894470")
ListArr=("${ListArr[@]}" false "3" "/etc/cron.daily/sun-hours" "Matches")
ListArr=("${ListArr[@]}" "http://askubuntu.com/questions/894460/automatically-adjust-display-brightness-based-on-sunrise-and-sunset/894470#894470")
ListArr=("${ListArr[@]}" false "4" "/home/rick/.conkyrc" "Matches")
ListArr=("${ListArr[@]}" "http://askubuntu.com/questions/894460/automatically-adjust-display-brightness-based-on-sunrise-and-sunset/894470#894470")
ListArr=("${ListArr[@]}" false "5" "/usr/local/bin/auto-brightness-config" "Matches")
ListArr=("${ListArr[@]}" "http://askubuntu.com/questions/894460/automatically-adjust-display-brightness-based-on-sunrise-and-sunset/894470#894470")
ListArr=("${ListArr[@]}" false "6" "/etc/cron.d/display-auto-brightness" "Matches")
ListArr=("${ListArr[@]}" "http://askubuntu.com/questions/894460/automatically-adjust-display-brightness-based-on-sunrise-and-sunset/894470#894470")
ListArr=("${ListArr[@]}" false "7" "/home/rick/bin/indicator-sysmonitor-display" "Different")
ListArr=("${ListArr[@]}" "http://askubuntu.com/questions/882419/can-bash-display-in-systray-as-application-indicator/882420#882420")

TransCount=0 # Number of Inserts, Edits and Deletes

# Read Only Status column: Recalc, Different, Matches, Bad File, No Address, Bad Address
# Debugging: --hide-column=2 hides Read Only record number column for normal operation

while true ; do

# adjust width & height below for your screen 900x600 default for 1920x1080 HD screen
# also adjust font="14" below if blue title text is too small or too large
Record=(`yad \
    --title "websync - Compare local scripts to those published on internet." --list \
        --text '<span foreground="blue" font="14"> \
        Click column heading to sort.\
        Select record before clicking: Insert / Edit / Delete</span>' \
        --width=1200 --height=600 --center --radiolist -separator="$IFS" \
        --button="Insert before":10 --button="Edit":20 --button="Delete":30 --button="Run":40 \
        --button="Cancel ALL":50 --button="Save":60 --search-column=3 \
        --column "Select" --column "Record number" --hide-column=2 --column "File Name" \
        --column "Status" --column " Website Address" \
        "${ListArr[@]}"`)
Action=$?

RecSelected=false
RecArr=()
i=0

# Button values 1 and 3 don't work for returning selected record for some reason???
# Button values 11, 13 and 15 don't work either. 12, 14 and 16 work. 
# Therefore use Button values (10, 20, 30...) for readability.
for Field in "${Record[@]}" ; do
    RecSelected=true
    RecArr[i++]=$Field
done

# Define variables for easy reading and fewer code line changes when expanding
RecArrCnt=5
ListArrCnt=${#ListArr[@]}

# Error checking
if [[ $Action == 10 ]] || [[ $Action == 20 ]] || [[ $Action == 30 ]] ; then
    if [[ $RecSelected == false ]] ; then
    zenity --error --text 'You must select a record before clicking: Insert / Edit / Delete.'
    continue
    fi
fi

# Insert before || or Edit ?
if [[ $Action == 10 ]] || [[ $Action == 20 ]] ; then

    RecArr[3]="Recalc"
    # --text="Set fields and click OK to update" 
    # Note if there is a space at end of line, next line generates invalid command error from yad
    NewRecArr=(`yad --width=900 --height=300 --title="Link file to Website Address" \
        --form --center \
        --field="File name":FL --field="Status":RO \
        --field="Website Address":TXT \
        ${RecArr[2]} ${RecArr[3]} ${RecArr[4]}`)
    ret=$?

    # Cancel =252, OK = 0
    # OK & Insert operation?
    if [[ $ret == 0 ]] && [[ $Action == 10 ]]; then
        # Create new list entry and renumber
    ((TransCount++)) # Update number of changes
        let i=1      # Base 0 array, record number is second field

    while [ $i -lt $ListArrCnt ] ; do
        if [ ${ListArr[$i]} -eq ${RecArr[1]} ]; then
        # We have matching record number to insert before
            NewArr+=( false )
            NewArr+=( "${ListArr[$i]}" )
            NewArr+=( "${NewRecArr[0]}" )
            NewArr+=( "${NewRecArr[1]}" )
            NewArr+=( "${NewRecArr[2]}" )
        fi
        let j=$(( $i-1 ))
        let k=$(( $j+$RecArrCnt ))
        while [ $j -lt $k ] ; do
            NewArr+=( "${ListArr[$j]}" )
        j=$(($j + 1))
        done
        let i=$(($i + $RecArrCnt)) # Next list array entry to copy
    done
    ListArr=("${NewArr[@]}")
    unset NewArr
    RenumberListArr

    # OK & Edit operation?
    elif [[ $ret == 0 ]] && [[ $Action == 20 ]]; then
        # Update array entry
    ((TransCount++))
        let i=1
    while [ $i -lt $ListArrCnt ] ; do
        if [ ${ListArr[$i]} -eq ${RecArr[1]} ]; then
        # We have matching record number
        ListArr[++i]="${NewRecArr[0]}"
        ListArr[++i]="New"
        ListArr[++i]="${NewRecArr[2]}"
        let i=$(($ListArrCnt + 1)) # force exit from while loop
        else
        let i=$(($i + $RecArrCnt)) # Check next entry
        fi
    done
    fi

# Delete record?
elif [[ $Action == 30 ]] ; then
    # --text="click OK to confirm delete" 
    # Note if there is a space at end of a script line, the next line generates 
    # "invalid command error from yad
    yad --width=900 --height=300 --title="Do you really want to delete this record?" \
        --text '<span foreground="blue" font="14">Click OK to confirm delete.</span>' \
        --form --center \
        --field="File name":RO --field="Status":RO \
        --field="Website Address":RO \
        ${RecArr[2]} ${RecArr[3]} ${RecArr[4]}
    ret=$?

    # Cancel =252, OK = 0
    if [[ $ret == 0 ]] ; then
        # Delete record from list array and renumber
    ((TransCount++))
        let i=1
    while [ $i -lt $ListArrCnt ] ; do
        if [ ${ListArr[$i]} -eq ${RecArr[1]} ]; then
        # We have matching record number
        j=$(($i - 1))
        k=$(($j + $RecArrCnt))
        while [ $j -lt $k ] ; do
            unset 'ListArr[$j]'
            j=$(($j + 1))
        done
        for i in "${!ListArr[@]}"; do
                NewArr+=( "${ListArr[$i]}" )
        done
        ListArr=("${NewArr[@]}")
        unset NewArr
        let i=$(($ListArrCnt + 1)) # force exit from while loop
        else
        let i=$(($i + $RecArrCnt)) # Check next entry
        fi
    done
    RenumberListArr
    else
        continue # cancel changes.
    fi

# Run update process?
elif [[ $Action == 40 ]] ; then
    continue # TODO: Run

# Cancel all changes?
elif [[ $Action == 50 ]] || [[ $Action == 252 ]] ; then
    # Cancel ALL || or X the window or Escape
    if [[ $TransCount -gt 0 ]] ; then
    zenity --question --text "You have made $TransCount change(s). Do you really want to cancel?"
    rc=$? 
    if [[ $rc -eq 0 ]] ; then
        exit
    fi
    else
    exit
    fi

# Save changes?
elif [[ $Action == 60 ]] ; then
    # Save
    echo ${ListArr[@]} > ~/bin/.websync
    exit
else
    zenity --error --text "~/bin/websync - Unknown button return code: $Action"
    exit
fi

done # End of while loop

IFS="$OLDIFS"

exit

Summary

Hopefully this saves others lots of time getting their own record management system going using bash and yad. Of course more bullet proof and probably faster methods can be done using Python or C but that probably comes at the expense of more lines of code and higher learning curve.

At the end of the day this project is targeted at those that want to learn more about bash and what can be accomplished in a bash-only environment.

Perhaps AskUbuntu is the wrong forum for posting this and Stack Overflow or Unix & Linux forums might be better Stack Exchange candidates. I look forward to comments on that as I'm really not sure the best place.

Of course I always look forward to general comments and constructive criticisms as well :)

Bash One-Liner – Display All `gsettings` in GUI Dialog Window

Yad works but not Zenity (yet)

I tried doing this with zenity but couldn't figure it out. I managed to make it work with yad but after a couple of clock days had to turn to google groups to get help from the yad experts. They fixed my one-liner bash code in 12 hours!

If you don't have yad installed already you need to use:

sudo apt install yad

yad lets you sort the list by any column in ascending/descending order. You can grab the scroll bar to quickly move up and down the list. The Up/Down arrow, PgUp, PgDn, Home and End keys navigate as expected.

The one-liner bash code

Here's the bash one-liner code you can copy and paste into your terminal window:

gsettings list-recursively | sed 's/  */\n/;s/  */\n/;s/\&/\&amp;/g' | yad --list --title "gsettings" --item-seperator='\n' --width=1800 --height=800 --wrap-width=600 --column=Group --column=Key --column=Setting --no-markup

This is for a 1080p display where the screen is 1920 pixels wide. If your screen is smaller, reduce the size of these arguments:

--width=1800 --height=800 --wrap-width=600

Sample output

When the yad scroll box opened I:

Clicked on the Group column heading to sort by group. Otherwise the order is random as gsettings list-recursively dumps out the database.
Scrolled down org.gnome.settings-daemon.plugins.power section.
Noticed a gsettings I've never seen before but might help me solve suspend problems I've encountered (as highlighted in screen shot below)

The one-liner pays for itself right away

Here is the new gsettings I discovered:

$ gsettings get org.gnome.settings-daemon.plugins.power lid-close-suspend-with-external-monitor
false

The gsettings contradicts a systemd setting I have:

$ cat /etc/systemd/logind.conf | grep -i lidswitchdock | grep -vF "#"
HandleLidSwitchDocked=suspend

dconf-editor a complete GUI application

There is also dconf-editor a full blown GUI you can use: What is dconf, what is its function, and how do I use it?

To summarize the link, install it using:

sudo apt install dconf-tools

The whole link is highly recommended reading and it covers gsettings in depth as well.