Is it possible to compare $ip_choice with a number without setting it before?
#!/bin/bash
ip_choice=999
while ! (( $ip_choice <= 233 ))
do
read -p "Enter a valid IP (1-256): " ip_choice
done
It work's like that - only I want to know if there is a more elegant possibility :-).
#!/bin/bash
while read -r -p "Enter a valid IP (1-256): " ip_choice; do
(( ip_choice >= 1 && ip_choice <= 256 )) && break
done
echo "${ip_choice}"
$ ./t.sh
Enter a valid IP (1-256): -1
Enter a valid IP (1-256): 0
Enter a valid IP (1-256): 257
Enter a valid IP (1-256): abc
Enter a valid IP (1-256): 20
20
You could make use of until:
until ((ip_choice >=1 && ip_choice <= 256)); do
read -p "Enter a valid IP (1-256): " ip_choice;
done
Quoting from help until:
until: until COMMANDS; do COMMANDS; doneExecute commands as long as a test does not succeed. Expand and execute COMMANDS as long as the final command in the `until' COMMANDS has an exit status which is not zero. Exit Status: Returns the status of the last command executed.
For example:
$ until ((ip_choice >=1 && ip_choice <= 256)); do
> read -p "Enter a valid IP (1-256): " ip_choice;
> done
Enter a valid IP (1-256): 0
Enter a valid IP (1-256): 298
Enter a valid IP (1-256): 242
