bash integer number only

Question

I can't seem to allow single integer input only. If someone puts abc, it will work.

But if someone puts in abc123 or 123abc it will still treat it as a valid integer

# input to be an integer.
validate_integer(){

    if [ !  "$#" -eq "1" ]; then
            error "Please enter one numberic value only"
            return 1
    elif [[ "$1" =~ ^[[:alpha:]]+$ ]]; then
            error "Input must be a NUMBER"
            return 1
    else
            return 0
    fi
}

Refer this. stackoverflow.com/questions/2210349/…

KeithSmith
– KeithSmith

2013-11-23 22:38:14 +00:00
Commented Nov 23, 2013 at 22:38 — KeithSmith
– KeithSmith, Commented Nov 23, 2013 at 22:38

janos · Accepted Answer · 2013-11-23 23:44:40Z

2

Change this line:

elif [[ "$1" =~ ^[[:alpha:]]+$ ]]; then

to this:

elif ! [[ "$1" =~ ^[[:digit:]]+$ ]]; then

There, ^[[:digit:]]+$ means the string must be composed of digits from beginning to end, and it must be 1 or more characters long. We negate this with !, to handle the case when the string does not satisfy this condition (not fully numeric).

answered Nov 23, 2013 at 23:44

janos

126k31 gold badges243 silver badges253 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

bash integer number only

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related