Perl: Can a string be converted to vector flag

Question

I've been looking for a way to iterate through Ip range and I come across this response

sub inc_ip { $_[0] = pack "N", 1 + unpack "N", $_[0] }
my $start = 1.1.1.1;
my $end = 1.10.20.30;
for ( $ip = $start; $ip le $end; inc_ip($ip) ) {
    printf "%vd\n", $ip;
}

What I want to knew is if there is a way to convert string like my $start = "192.168.1.1"; to vector flag. What I get when I pass a string is some random numbers

I don't understand what this *"vector flag"* where you get some *"random numbers"* is you are talking about. And I cannot see anything in your code which matches this description. It is not clear from your question what you expect to happen and what you get instead. — Steffen Ullrich, Jan 03 '20 at 19:20
If `my $start = 1.1.1.1;` ain't a vector flag? then what type of data it is? — Mobrine Hayde, Jan 03 '20 at 19:21
Yeah it is, but I want to format a string to be a vector flag — Mobrine Hayde, Jan 03 '20 at 19:22
I have no idea what this "vector flag" thing is you want. Please show what you expect the program to produce. — Steffen Ullrich, Jan 03 '20 at 19:23
https://perldoc.perl.org/functions/sprintf.html, it is a format — Mobrine Hayde, Jan 03 '20 at 19:24
There is no "convert to vector flag". This "vector flag" is a modifier ("flag") for `printf` to print the given value in a specific way. I still don't have any idea what you want your program to produce. — Steffen Ullrich, Jan 03 '20 at 19:30
I want to enter an IP address as a string and pass it to `inc_ip()` and do the same work of the code — Mobrine Hayde, Jan 03 '20 at 19:33
`Socket::inet_aton("1.2.3.4")` gives you the binary representation - which is what you likely want (don't forget `use Socket;`). — Steffen Ullrich, Jan 03 '20 at 19:37
Your code is a bit tricky because your `$start` and `$end` variables are Version strings which carry some magic in perl... — clamp, Jan 03 '20 at 19:38

ikegami · Accepted Answer · 2020-01-08T23:01:50.323

3

pack 'C*', split /\./, $s

Or for IPv4 specifically,

use Socket qw( inet_aton );

inet_aton($s)

For example, you could use

use Socket qw( inet_aton );

my $start = unpack('N', inet_aton('1.1.1.1'));
my $end   = unpack('N', inet_aton('1.10.20.30'));

for my $ip ($start..$end) {
   printf("%vd\n", pack('N', $ip));
}

edited Jan 08 '20 at 23:01

answered Jan 04 '20 at 05:51

ikegami

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Added to my answer. – ikegami Jan 08 '20 at 23:02

Perl: Can a string be converted to vector flag

1 Answers1