morse script 1

Last night I got it to the point where it'd take single characters of user input and play them as a long beep if 1, a short beep if 0 and error if other.

It would only take one digit at a time though; a string of digits was rejected.

At that stage it looked like this:

#!/bin/bash

echo "Enter a sequence of 1s and 0s representing dashes and dots:"

read user_input

for x in $user_input; do

        if [[ $x = 1 ]]

        then beep -l 300 -D 50

        elif [[ $x = 0 ]]

        then beep -l 150 -D 50

        else echo "$x is not an acceptable character"

        fi

done

I recognise that this is poorly formed. Anyway, I need it to iterate over each character in the user input. I see references to sed and awk and whatnot, and I don't understand that stuff, so I'm going to use the most basic form I can. I found the answer here:

You can use a traditional for loop:
foo=string
for (( i=0; i<${#foo}; i++ )); do echo ${foo:$i:1}done${#foo} expands to the length of foo. ${foo:$i:1} expands to the substring starting at position $i of length 1.

So now I have the following, which seems to be working OK:

#!/bin/bash

echo "Enter a sequence of 1s and 0s representing dashes and dots:"

read user_input

# iterate over each character in the string

for (( i=0; i<${#user_input}; i++ )); do

# beep long, short or reject input

# for x in $user_input; do

        if [[ ${user_input:$i:1} = 1 ]]

        then beep -l 300 -D 50

        elif [[ ${user_input:$i:1} = 0 ]]

        then beep -l 150 -D 50

        else echo "${user_input:$1:1} is not an acceptable character"

        fi

done

It was only in the second verison that I actually extended the beep lengths and added a delay after each one. originally the commands were beep -l 100 and beep -l 50 respectively. extending these to 300 and 150 with a -D delay of  50 after each repetition (of which there is only one per beep command, so it only added 50 after each beep). 

Next steps:

* get it to read from the morse text file using a similar method?

* reverse the order so it's asking for input instead of taking it

* put something in to account for upper and lower case letters

* put in speed variables?

* define a function for beep to optimise code?

* design custom beep commands for each letter?

* how can I measure the efficiency of a script to decide?

Also:

* write in python?

* write in C++?