How to efficiently convert long int to dotted quad IP in bash

Question

I have a lot of IP addresses in a large mysql DB stored as long int's. I need an efficient/quick way to convert them back to an IP within a BASH shell script ( or have mysql return the results as an IP?? ).

Note: specifically don't want to call perl, awk, or other 'language'.

Answer 1

See the INET_NTOA function, you can use that to convert the number to an IP on the MySQL server.

Answer 2

Suppose you have a field called ip_addr in a table called hosts

Then

select INET_NTOA(ip_addr) from hosts;

Would do the query and return dotted quad IPs in the result set.

Answer 3

Since you asked for Bash:

INET_NTOA() { 
    local IFS=. num quad ip e
    num=$1
    for e in 3 2 1
    do
        (( quad = 256 ** e))
        (( ip[3-e] = num / quad ))
        (( num = num % quad ))
    done
    ip[3]=$num
    echo "${ip[*]}"
}

INET_ATON ()
{
    local IFS=. ip num e
    ip=($1)
    for e in 3 2 1
    do
        (( num += ip[3-e] * 256 ** e ))
    done
    (( num += ip[3] ))
    echo $num
}

Examples:

$ INET_ATON 10.2.1.255
167903743
$ INET_NTOA 167903743
10.2.1.255