BASH scripts : whiptail file select - bash

Question

I've found a great little program that will allow me to add user friendly GUI's to my Bash Scripts;
whiptail
However the whiptail man page isn't all that helpful and doesn't provide any examples. After doing some google searches I understand how to create a simple yes/no menu using whiptail:
#! /bin/bash
# http://archives.seul.org/seul/project/Feb-1998/msg00069.html
if (whiptail --title "PPP Configuration" --backtitle "Welcome to SEUL" --yesno "
Do you want to configure your PPP connection?" 10 40 )
then
echo -e "\nWell, you better get busy!\n"
elif (whiptail --title "PPP Configuration" --backtitle "Welcome to
SEUL" --yesno " Are you sure?" 7 40)
then
echo -e "\nGood, because I can't do that yet!\n"
else
echo -e "\nToo bad, I can't do that yet\n"
fi
But what I would really like to build a file select menu using whiptail to replace some old code I have in a few different backup/restore bash scripts I have:
#!/bin/bash
#This script allows you to select a file ending in the .tgz extension (in the current directory)
echo "Please Select the RESTORE FILE you would like to restore: "
select RESTOREFILE in *.tgz; do
break #Nothing
done
echo "The Restore File you selected was: ${RESTOREFILE}"
I assume this has to be done via the '--menu' option of whiptail, but I am not sure how to go about it?
Any pointers?
Or can you point me in the direction of some whiptail examples?

Answer 1

Build an array of file names and menu select tags:
i=0
s=65 # decimal ASCII "A"
for f in *.tgz
do
# convert to octal then ASCII character for selection tag
files[i]=$(echo -en "\0$(( $s / 64 * 100 + $s % 64 / 8 * 10 + $s % 8 ))")
files[i+1]="$f" # save file name
((i+=2))
((s++))
done
A method like this will work even if there are filenames with spaces. If the number of files is large, you may have to devise another tag strategy.
Using alpha characters for the tags lets you press a letter to jump to the item. Numeric tags don't seem to do that. If you don't need that behavior, then you can eliminate some complexity.
Display the menu:
whiptail --backtitle "Welcome to SEUL" --title "Restore Files" \
--menu "Please select the file to restore" 14 40 6 "${files[#]}"
If the exit code is 255, the dialog was canceled.
if [[ $? == 255 ]]
then
do cancel stuff
fi
To catch the selection in a variable, use this structure (substitute your whiptail command for "whiptail-command"):
result=$(whiptail-command 2>&1 >/dev/tty)
Or
result=$(whiptail-command 3>&2 2>&1 1>&3-)
The variable $result will contain a letter of the alphabet that corresponds to a file in the array. Unfortunately, Bash prior to version 4 doesn't support associative arrays. You can calculate the index into the array of the file from the letter like this (notice the "extra" single quote):
((index = 2 * ( $( printf "%d" "'$result" ) - 65 ) + 1 ))
Example:
Welcome to SEUL
┌──────────┤ Restore Files ├───────────┐
│ Please select the file to restore │
│ │
│ A one.tgz ↑ │
│ B two.tgz ▮ │
│ C three.tgz ▒ │
│ D another.tgz ▒ │
│ E more.tgz ▒ │
│ F sp ac es.tgz ↓ │
│ │
│ │
│ <Ok> <Cancel> │
│ │
└──────────────────────────────────────┘

Answer 2

Whiptail is a lightweight reimplementation of the most popular features of dialog, using the Newt library. I did a quick check, and many features in Whiptail seem to behave like their counterparts in dialog. So, a dialog tutorial should get you started. You can find one here but Google is your friend of course. On the other hand, the extended example probably contains a lot of inspiration for your problem.

Answer 3

This function is part of my function repository for whiptail
# ----------------------------------------------------------------------
# File selection dialog
#
# Arguments
# 1 Dialog title
# 2 Source path to list files and directories
# 3 File mask (by default *)
# 4 "yes" to allow go back in the file system.
#
# Returns
# 0 if a file was selected and loads the FILE_SELECTED variable
# with the selected file.
# 1 if the user cancels.
# ----------------------------------------------------------------------
function dr_file_select
{
local TITLE=${1:-$MSG_INFO_TITLE}
local LOCAL_PATH=${2:-$(pwd)}
local FILE_MASK=${3:-"*"}
local ALLOW_BACK=${4:-no}
local FILES=()
[ "$ALLOW_BACK" != "no" ] && FILES+=(".." "..")
# First add folders
for DIR in $(find $LOCAL_PATH -maxdepth 1 -mindepth 1 -type d -printf "%f " 2> /dev/null)
do
FILES+=($DIR "folder")
done
# Then add the files
for FILE in $(find $LOCAL_PATH -maxdepth 1 -type f -name "$FILE_MASK" -printf "%f %s " 2> /dev/null)
do
FILES+=($FILE)
done
while true
do
FILE_SELECTED=$(whiptail --clear --backtitle "$BACK_TITLE" --title "$TITLE" --menu "$LOCAL_PATH" 38 80 30 ${FILES[#]} 3>&1 1>&2 2>&3)
if [ -z "$FILE_SELECTED" ]; then
return 1
else
if [ "$FILE_SELECTED" = ".." ] && [ "$ALLOW_BACK" != "no" ]; then
return 0
elif [ -d "$LOCAL_PATH/$FILE_SELECTED" ] ; then
if dr_file_select "$TITLE" "$LOCAL_PATH/$FILE_SELECTED" "$FILE_MASK" "yes" ; then
if [ "$FILE_SELECTED" != ".." ]; then
return 0
fi
else
return 1
fi
elif [ -f "$LOCAL_PATH/$FILE_SELECTED" ] ; then
FILE_SELECTED="$LOCAL_PATH/$FILE_SELECTED"
return 0
fi
fi
done
}
The use is simple
if dr_file_select "Please, select a file" /home/user ; then
echo "File Selected: \"$FILE_SELECTED\"."
else
echo "Cancelled!"
fi

Answer 4

I've tried following, which worked:
whiptail --title "PPP Config" --backtitle "Welcome to SEUL" --menu YourTitle 20 80 10 `for x in $(ls -1 *.tgz); do echo $x "-"; done`
you might change this into a multiple-liner as well, i've added checking for empty list:
MYLIST=`for x in $(ls -1 *.tgz); do echo $x "-"; done`
WC=`echo $MYLIST | wc -l`
if [[WC -ne 0]]; then
whiptail --title "PPP Config" --backtitle "Welcome to SEUL" --menu YourTitle 20 80 10 $MYLIST
fi
you need to adjust the numbers in order to get a cleaninterface. And you may replace the "-" by anything else if you want to. But if you don't, you will see 2 entries per line.
By the way: The selected entry is printed onto stderr.
This could need some more improving, but for a basic idea I think it's enough.

Answer 5

This seems to be one of the top results when you search for whiptail, and none of the previous results worked for me. This is what I wound up using:
#! /bin/bash
shopt -s nullglob
dir=`pwd`
cd /path/to/files
arr=(*.tgz)
for ((i=0; i<${#arr[#]}; i++)); do j=$((2*$i+2)); a[j]="${arr[$i]}"; a[j+1]=""; done
a[0]=""
# Next line has extra spaces at right to try to center it:
a[1]="Please make a selection from the files below "
result=$(whiptail --ok-button "OK button text" --cancel-button "Cancel Button Text" --title "Title Text" --backtitle "Text at upper left corner of page" --menu "Menu Text (not used??)" 30 160 24 "${a[#]}" 2>&1 >/dev/tty)
if [[ $? = 0 ]]
then
# ge 5 in next line should be length of file extension including . character, plus 1
[ ${#result} -ge 5 ] && outfile="/path/to/files/$result" || echo "Selection not made"
fi
cd "$dir"
$result will be empty if no valid selection was made. I added a dummy selection at the top of the list that returns an empty string as a result, so that you won't accidentally select the wrong file by accidentally hitting Enter right after the menu comes up. If you don't want that, then in the "for" line remove the +2 in "do j=$((2*$i+2))" and also the following two lines that set a[0] and a[1] explicitly.
The confusing thing about whiptail is that when reading from an array in a situation like this it expects two data items per line, both of which are displayed, the first being the result you want returned if the line is expected (which in some situations might be a letter or a number) and the second being whatever descriptive text you may want. That's why for the first line I use a[0] to give an empty string as the result, and a[1] as the descriptive text, but from there on the first item in the pair contains the filename (which is what I actually want returned) and the second is an empty string, since I don't want to display any text other than the filename on those lines.
Also a previous post said whiptail returned an error code of 255 if the cancel button was pressed, but that was not the case for the version I have - it returns 1. So I just test for an error code of 0 and if it is I assume it may be a valid entry, then I test for a valid string length (more than just the number of characters in the file extension, including the . character) to be sure.