Krdytkyu

I'm thinking about creating a bash script where multiple options can be specified and at the end define the variables according to the chosen options or execute certain orders when receiving the different options. An example is worth more than a thousand words:

[X] Copy only (1) - Options typed by the user

[ ] Move only (2)

[X] Checksum  (3) - Options typed by the user

[ ] Reset permission (4)

[ ] Exit (5)



Select choice:

I have found some options but I do not know how to make them do a certain function because I do not understand how the code works.

Update:

Code functional:

#!/bin/bash



#Contributing code by Sergiy Kolodyazhnyy and adaptation for MarianoM.



resize -s 40 90 > /dev/null #Change window size.



option=$(dialog --clear --backtitle "Synchronization..." --title "Synchronize" 

    --checklist "Select the synchronization options:"  20 50 10 

       checksum "Compare the content" off 

       detail "Show more information" off 

       directory "Synchronize folders" on 

       recursive "Include subfolders" off 2>&1 > /dev/tty)



for i in $option; do #Set parameter of the menu options.

       case $i in

         checksum) c="-c" ;;

         detail) v="-v" ;;

         directory) d="-d" ;;

         recursive) r="-r" ;;

       esac

     done



if [ -z $option ]; then #Check if the variable is empty. If it is empty, it means that the user has not chosen an option.

 clear 

 echo

 echo "Error: No option has been selected or dialog not installed. The program can not continue."

 echo  

   else

 clear

   source=$(dialog --clear --backtitle "Please select source..." --title "Source:" --fselect "" 20 50 2>&1 > /dev/tty)

     if [ -z $source ]; then

       clear

       echo

       echo "Error program. Source not selected, try again!"

       echo

       exit

     fi

 clear

 destination=$(dialog --clear --backtitle "Please select destination..." --title "Destination:" --fselect "" 20 50 2>&1 > /dev/tty)

     if [ -z $destination ]; then

       clear

       echo

       echo "Error program. Destination not selected, try again!"

       echo

       exit

     fi

 clear

 rsync  "$c" "$v" "$d" "$r" "$source" "$destination"

 echo

fi

exit

From the discussion in the comments it is apparent that your main concern is to create as script with multiple selections, rather than focus on copying/moving files themselves, and the file operations are just an example. This functionality can be achieved via dialog command, which allows creating text user interfaces, with --checklist flag specifically; however there's nothing in the standard shell-only toolbox to achieve what you want. Hence, dialog is an appropriate tool for this job.

Below you will find an example script. While the script implements only 3
options that were discussed, it provides a decent starting point which users can extent further, and also addresses mutually exclusive options as mentioned in the comments. Particularly, the multiple selection is addressed in menu() function, which serves as a wrapper for dialog with --checklist option

To keep things simple, all you really need is this:

output=$(dialog --clear --backtitle "Backtitle. Use <SPACE> to select." --title "My Dialog" 

       --checklist "Select all that apply"  50 50 100 

       checksum "SHA-256" off 

       copy "Copy only (exclusive with move)" off 

       move "Move only (exclusive with copy)" off 2>&1 > /dev/tty)

This saves the selection of multiple items to variable $output. Note that `2>&1 > /dev/tty) at the end are crucial to saving the return value into variable. But see the script below for more practical example:

#!/bin/bash



puke(){

    # function to exit with specific error message

    # analogous to 'die' in Perl

    printf ">>> Errors were encountered: %sn" "$1" && exit

} > /dev/stderr



menu(){

    # dialog --help documents the option as follows:

    # --checklist    <text> <height> <width> <list height> <tag1> <item1> <status1>...

    # tags are what the output returns.

    # We can use word-splitting 

    # and iterate over output of this function in order. Of course first option

    # being checksum will always work and is not mutually exclusive with anything else

    dialog --clear --backtitle "Backtitle. Use <SPACE> to select." --title "My Dialog" 

           --checklist "Select all that apply"  50 50 100 

           checksum "SHA-256" off 

           copy "Copy only (exclusive with move)" off 

           move "Move only (exclusive with copy)" off || puke



} 2>&1 1>/dev/tty



select_file(){

    dialog --backtitle "Choose file by typing or navigating and selecting with <SPACE>" --fselect "/etc/" 

           20 50  || puke

} 2>&1 1>/dev/tty





iter_actions(){

    # variables are available to child functions

    # Since we call iter_actions in main(), this

    # function also knows about main's variable $fselect



    for i ; do 

       case "$i" in

           checksum) sha256sum "$fselect" ;;

           copy) cp "$fselect" /tmp ;;

           move) mv "$fselect" /tmp ;;

       esac

    done

}



main(){

    # here I'm using /etc but you can use $PWD to default to user's 

    # current working directory, or accept positional parameters from command-line

    # as in $1, $2 and so forth

    fselect=$( select_file "/etc" )

    actions=$(menu) 

    printf "r%b" "33c" # this clear the screen



    case "$actions" in

       *copy*move|*move*copy) puke "Mutually exclusive options selected" ;;

        *) iter_actions $actions ;; # note here variable is unquoted on purpose

    esac

}



# script entry point

main "$@"

For further research:

• How can I create a select menu in a shell script?


• How to get dialog box input directed to a variable?
  


• Why write an entire bash script in functions?