java-tutorials/linux-bash/read/src/main/bash/read_inputs.sh

#!/bin/bash

# section 2.1
default_read(){
    read input1 input2 input3
    echo "[$input1] [$input2] [$input3]"
}

# section 2.2
custom_ifs_no_array(){
    OLDIFS=$IFS
    IFS=";"
    read input1 input2 input3
    echo "[$input1] [$input2] [$input3]"
    # restore default IFS after we're finished so current shell behaves like before
    IFS=$OLDIFS
}

# Section 2.3
prompt_read_password(){
    prompt="You shall not pass:"
    read -p "$prompt" -s input
    echo -e "\ninput password [$input]"
}

array_read(){
    declare -a input_array
    text="baeldung is a cool tech site"
    read -e -i "$text" -a input_array 
    for input in ${input_array[@]} 
        do
            echo " word [$input]"
        done
}

# section 3.1
file_read(){
    exec {file_descriptor}<"./file.csv"
    declare -a input_array
    delimiter=";"
    while IFS="," read -a input_array -d $delimiter -u $file_descriptor 
        do
            echo "${input_array[0]},${input_array[2]}" 
        done
    exec {file_descriptor}>&-
}

# section 3.2
command_pipe(){
    ls -ll / | { declare -a input
               read
               while read -a input; 
               do
                   echo "${input[0]} ${input[8]}"
               done }
}

# section 3.3
timeout_input_read(){
    prompt="You shall not pass:"
    read -p "$prompt" -s -r -t 5 input
        if [ -z "$input" ]; then
            echo -e "\ntimeout occured!"
        else
            echo -e "\ninput word [$input]"
        fi
}

exactly_n_read(){
    prompt="Reading exactly 11 chars:"
    read -p "$prompt" -N 11 -t 5 input1 input2 
    echo -e "\ninput word1 [$input1]"
    echo "input word2 [$input2]"
}

# main menu entry point
echo "****Read command samples menu*****"
PS3="Your choice (1,2,3 etc.):"
options=("default_read" "custom_ifs_no_array" "prompt_read_password" \
         "array_read" "file_read" "command_pipe" "timeout_input_read" \
         "exactly_n_read" "quit")
select option in "${options[@]}"
do
  case $option in
        "default_read")
            echo "Enter something separated by spaces"
            default_read
            ;;
        "custom_ifs_no_array")  
            echo "Enter something separated by ;"
            custom_ifs_no_array
            ;;
        "prompt_read_password")
            echo "Enter an invisible password after the prompt"
            prompt_read_password
            ;;
        "array_read")
            echo "Enter something else or just return"
            array_read
            ;;
        "file_read")
            echo "Reading from one liner csv file"
            file_read
            ;;
        "command_pipe")
            echo "Listing files and access rights from /"
            command_pipe
            ;;
        "timeout_input_read")
            echo "Enter something in 5 seconds or less"
            timeout_input_read
            ;;
        "exactly_n_read")
            echo "Enter at least 11 characters or wait 5 seconds"
            exactly_n_read
            ;;
        "quit")
            break
            ;;
        *) echo "Invalid option";;
  esac
done