AppleScript: problems reading from a file - macos

Question

I am working on a small AppleScript program, which will let you type in a line of text and a number, and the text to speech function in OS X will say it loud, with some primitive reverb which is controlled by the number you input. (Study my code for details.)
Everything works out fine, except for one thing. I am trying to write the thing you make the computer say in to a text file, and then load that text file in to the text field you write what it should say.
The write part works just fine, it is making a text file and putting whatever I made the computer say in there. The problem is with the read.
As it is now, the read part looks like this:
try
open for access prevSFile
set defToSay to (read prevSFile)
end try
Nothing happens at all. If I try to remove the 'try', it gives me the error -500, and the program stops.
Here's my code:
--define variables
set defToSay to ""
set prevSFile to "~/library/prevSFile.txt"
--Fetch info from save file:
try
open for access prevSFile
set defToSay to (read prevSFile)
end try
--Display dialoges:
display dialog "What do you want to say?" default answer defToSay
set whatToSay to the text returned of the result
display dialog "How many times do you want to overlay it?" default answer "5"
set overlays to the text returned of the result
--Create/edit save file:
do shell script "cd /"
try
do shell script "rm " & prevSFile
end try
do shell script "touch " & prevSFile
do shell script "echo " & whatToSay & " >> " & prevSFile
--Say and kill:
repeat overlays times
tell application "Terminal"
do script "say " & whatToSay
end tell
delay 0.01
end repeat
delay (length of whatToSay) / 5
do shell script "killall Terminal"

Answer 1

Your problem is here. AppleScript paths do not use "/" and AppleScript certainly doesn't know "~".
"~/library/prevSFile.txt"
Here's what that part of the code should be...
set prevSFile to (path to home folder as text) & "Library:prevSFile.txt"
try
set defToSay to (read file prevSFile)
end try
Now that you have the proper path for AppleScript you need to fix the paths for the shell commands. Note that you do not need to rm and touch a file every time. Just use ">" when you redirect the echo command and that will overwrite the file. You also need to use the "quoted form" of paths in case there's spaces.
do shell script "echo " & quoted form of whatToSay & " > " & quoted form of POSIX path of prevSFile
However you're doing a lot of unnecessary stuff in that script. Here's how I would write your code. Good luck.
property whatToSay : ""
property numberOfTimes : 5
--Display dialoges:
display dialog "What do you want to say?" default answer whatToSay
set whatToSay to the text returned of the result
repeat
display dialog "How many times do you want to overlay it?" default answer (numberOfTimes as text)
try
set numberOfTimes to the (text returned of the result) as number
exit repeat
on error
display dialog "Please enter only numbers!" buttons {"OK"} default button 1
end try
end repeat
repeat numberOfTimes times
say whatToSay
end repeat