form dialog | how to create userfriendly menu

https://bash.cyberciti.biz/guide/The_form_dialog_for_input

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• The form dialog displays data entry form which consisting of labels and fields.
• You can set the field length.
• An operator can use up/down arrows to move between fields and tab to move between windows.

The syntax is as follows:

dialog --form text height width formheight [ label y x item y x flen ilen ]

• Where,
  • The field length flen and input-length ilen tell how long the field can be.
  • If flen is zero, the corresponding field cannot be altered. and the contents of the field determine the displayed-length.
  • If flen is negative, the corresponding field cannot be altered, and the negated value of flen is used as the displayed-length.
  • If ilen is zero, it is set to flen.

Example

• Create a shell script called useradd1.sh:

#!/bin/bash
# useradd1.sh - A simple shell script to display the form dialog on screen
# set field names i.e. shell variables
shell=""
groups=""
user=""
home=""

# open fd
exec 3>&1

# Store data to $VALUES variable
VALUES=$(dialog --ok-label "Submit" \
   --backtitle "Linux User Managment" \
   --title "Useradd" \
   --form "Create a new user" \
15 50 0 \
 "Username:" 1 1 "$user"  1 10 10 0 \
 "Shell:"    2 1 "$shell"   2 10 15 0 \
 "Group:"    3 1 "$groups"   3 10 8 0 \
 "HOME:"     4 1 "$home"  4 10 40 0 \
2>&1 1>&3)

# close fd
exec 3>&-

# display values just entered
echo "$VALUES"

Save and close the file. Run it as follows:

chmod +x useradd1.sh
./useradd1.sh

Sample outputs:

• useradd1.sh: shell script output (the dialog command with data entry form)
• 

  The form dialog box in action
 
• 

  Displaying output stored in $VALUES