[Bash] Improving menu selection

[abbatrombone]

I am making a menu and was curious if there was a way to make it so quit was q rather than the last number. I have tried REPLY = "q" rather than

Code: Select all

REPLY = 1 + ${#sorted_options[@]} 

which did not work. I tried a case statement but was not able to get it working.

The code (please steal if you find it helpful):

Code: Select all

#!/bin/bash

##Menu for files
prompt="Please select a file to compile or run:"
options=( $(cd Java_Files && find . -maxdepth 1 -type f -name "*.java") )
##code that sorts
IFS=$'\n' sorted_options=($(sort <<<"${options[*]}"))
unset IFS ##unset, undefines a variable


PS3="$prompt "
select opt in "${sorted_options[@]}" "Quit" ; do
    if (( REPLY = 1 + ${#sorted_options[@]}  )) ; then
        exit

    elif (( REPLY > 0 && REPLY <= ${#sorted_options[@]} )) ; then
        echo  "You picked $opt which is file $REPLY"
        break

    else
        echo "Invalid option. Try another one."
    fi
done

## this grabs the file name you selected
file=$opt

##This searches for the .java file to see if it exists
##This is unneeded but is here being its working code i can use in the future

search_dir= "" ##put your dir here
file_name=$file

if [[ -d "$search_dir" ]]; then
  if [[ -f "$search_dir/$file_name" ]]; then
    echo "File $file_name exists in directory $search_dir."
	  else
    echo "File $file_name does not exist in directory $search_dir."
  fi
else
  echo "Directory $search_dir does not exist."
fi

##This searches for the .class to see if it exists

fileClass=$opt
fileClass=${fileClass//.java/}
fileClass+=".class"

if [[ -d "$search_dir" ]]; then
  if [[ -f "$search_dir/$fileClass" ]]; then
  echo "File $fileClass exists in directory $search_dir." && classExists="y"
	
  else
echo "File $fileClass does not exist in directory $search_dir." && classNotExists='y'
	
  fi
else
  echo ""
fi

##This next segment needs to be edited so if .class does not exist it compiles and then does java $file

##Compiles code if class does not exist
if [[ "$classNotExists" = "y" ]]; then
cd $search_dir && javac $file;
sleep 1 && cd $search_dir && java $file; ##has not been tested
fi

##Compiles the code if you say yes
if [[ "$classExists" = "y" ]]; then
echo "would you like to recompile the java code? y/n"
read -r Answer
fi

if [[ "$Answer" =~ [yY] ]]; then
cd  $search_dir && javac $file;
java $file
fi

##Just runs the code if you say no
if [[ "$Answer" =~ [nN] ]]; then
cd $search_dir && java $file && java $file
fi

[fabien]

The problem is a simple mistake: = assigns a value, == is a comparison operator.

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$> declare -i num=5
$> (( num == 6 )) || echo $num
5
$> (( num = 6 )) && echo $num
6

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#!/bin/bash

prompt="Please select a file to compile or run:"
options=( "javaFile2.java" "java  File1.java" "javaFile0.java" )
### change IFS in the subshell only
readarray -t sorted_options < <(IFS=$'\n'; sort <<<"${options[*]}")

PS3="$prompt "
select opt in "${sorted_options[@]}" "Quit" ; do
   if [[ "$REPLY" =~ ^[qQ](uit)*$ ]] || (( REPLY == 1 + ${#sorted_options[@]} )); then
      exit
   elif (( REPLY > 0 && REPLY <= ${#sorted_options[@]} )) ; then
      echo  "You picked $opt which is file $REPLY"
      break
   else
      echo "Invalid option. Try another one."
   fi
done

Note that this works because non-digits are evaluated to 0

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$> declare -i num
$> myvar=w; (( myvar == 0 )) && echo myvar
w
$> num=w; (( num == 0 )) && echo $num
0

[abbatrombone]

That worked wonderfully. Is there any way so that it displays as q) Quit at all or does

Code: Select all

select opt in

lock me into a numerical value?

[fabien]

Is there any way so that it displays as q) Quit at all or does

Code: Select all

select opt in

lock me into a numerical value?

The manual is quite clear, I'm afraid

select name [ in word ] ; do list ; done
The list of words following in is expanded, generating a list of items, and the set of expanded words is printed on the standard error, each preceded by a number.

select is handy, but if you want something more advanced you'll have to code it.