# How to ask users ("readline()") to provide a range?
**URL:** https://discourse.julialang.org/t/how-to-ask-users-readline-to-provide-a-range/3924
**Category:** General Usage
**Tags:** question
**Created:** [May 25, 2017, 3:07pm UTC](https://discourse.julialang.org/t/how-to-ask-users-readline-to-provide-a-range/3924 "2017-05-25T15:07:43Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)
#### Post date: [May 25, 2017, 3:07pm UTC](https://discourse.julialang.org/t/how-to-ask-users-readline-to-provide-a-range/3924/1 "2017-05-25T15:07:43Z")
I need to ask users to provide a range, in the form of Start:Step:End, from command line…
I tought to `parse(StepRange,readline(())`, but it doesn’t work:
```julia
print("Please specify a range in the form Start:Step:End (default to 20:1:25) ? ")
rawinput = readline()
rawinput = chomp(rawinput)
groups = []
if rawinput == ""
groups = collect(20:1:25)
else
groups = collect(parse(StepRange{Int64,Int64}, rawinput))
end
println(groups)
```
---
### Author:  [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)
#### Post date: [May 25, 2017, 3:13pm UTC](https://discourse.julialang.org/t/how-to-ask-users-readline-to-provide-a-range/3924/2 "2017-05-25T15:13:25Z")
got it…
```julia
print("Please specify a range in the form Start:Step:End (default to 20:1:25): ")
rawinput = readline()
rawinput = chomp(rawinput)
groups = []
if rawinput == ""
groups = collect(20:1:25)
else
groups= collect(eval(parse(rawinput)))
end
println(groups)
```
---
### Author:  [@kristoffer.carlsson](https://discourse.julialang.org/u/kristoffer.carlsson)
#### Post date: [May 25, 2017, 3:40pm UTC](https://discourse.julialang.org/t/how-to-ask-users-readline-to-provide-a-range/3924/3 "2017-05-25T15:40:58Z")
`eval` feels unnecessary here. Can’t you just split on `:` and parse the left and right side as ints and then construct the range.
---
### Author:  [@dpsanders](https://discourse.julialang.org/u/dpsanders)
#### Post date: [May 25, 2017, 7:40pm UTC](https://discourse.julialang.org/t/how-to-ask-users-readline-to-provide-a-range/3924/4 "2017-05-25T19:40:55Z")
Don’t ask them for input like this, just provide a function that they can call where they provide a range as the argument.
---
### Author:  [@tamasgal](https://discourse.julialang.org/u/tamasgal)
#### Post date: [May 25, 2017, 8:09pm UTC](https://discourse.julialang.org/t/how-to-ask-users-readline-to-provide-a-range/3924/5 "2017-05-25T20:09:23Z")
I also think splitting on `:` (like Kristoffer proposed) is the better option. Remember, eval can be evil on user input…