Validation of data entry in REXX

Question

How to enter only integers in REXX. The program I have manages to avoid some entries, but when the number contains a character such as a comma, percentage, cipher, among others, it causes the program to stop. How to validate these operations and let the program operate only with integer input.

do forever
  call charout, "Enter number: "
  pull NumInt
  say

  if (NumInt\== '') then 
    do
      if (datatype(value(NumInt), 'W')) then 
        leave
      else 
      do
        say "Error: Enter only whole number."
        say
      end
    end
  else
    do
      say "Error: <Enter> key accidentally triggered."
      say
    end
end

say "Valid input provided: " || NumeroInteiro

say
call charout, "Press <Enter> to finish... "
pull

exit

Answer 1

Based on the structure of your program, I believe you want something like:

charSpecial: procedure
arg String
Char = "!@#$%^&*()-_=+[]{}|;:',<>/?`~" || '"'
do i = 1 to length(Char)
  if pos(substr(Char, i, 1), String) > 0 then 
    return 1
end
return 0

See the use of this in the code:

do forever
  call charout, "Enter number: "
  pull NumInt
  say

  if (NumInt \== '') then 
    do
      if (charSpecial(NumInt)) then 
        do
          say "Error: Special character not allowed."
          say
        end
      else 
        if (datatype(value(NumInt), 'W')) then 
          leave
        else 
          do
            say "Error: Enter only whole number."
            say
          end
    end
  else
    do
      say "Error: <Enter> key accidentally triggered."
      say
    end
end

say "Valid input provided: " || NumInt

say
call charout, "Press <Enter> to finish... "
pull

exit