sprintf to hash

teamassociated has asked for the wisdom of the Perl Monks concerning the following question:

Been trying to figure out why this code is not storing my sprintf output. Please help! Thx!!!


use strict;
use warnings;

$lsmapFH = new FileHandle "/usr/ios/cli/ioscli lsmap -vadapter $option
+s[4] |" or die $!;
    while (<$lsmapFH>) {
       if (/no virtual device found/i) {
          warn "\n\nThis vhost $options[4] has no clients using me, tr
+y again with a correct vhost #!\n\n";
            die $!;
        }
        chomp;
        $vh    = (split)[0] if /^vhost/i;
        $clid  = (split)[2] if /^vhost/i;
        $cltid = sprintf "%d", $clid;
    }
    $lsmapHash{$vh} = {
        'clientID' => $cltid,
    };
}
use Data::Dumper;
print Dumper \%lsmapHash;

$VAR1 = {
          'vhost10' => {
                         'clientID' => '0'
                       }

works fine in CLI:
# perl -le '$clid=0x0000000a; $cltid= sprintf "%d", $clid; print $clti
+d;'
10


__SAMPLE_OUTPUT__ from lsmap

SVSA            Physloc                                      Client Pa
+rtition ID
--------------- -------------------------------------------- ---------
+---------
vhost10         U9117.MMD.218A8B7-V1-C2                     0x0000000b

VTD                   vtscsi25
Status                Available
LUN                   0x8100000000000000
Backing device        l02duapXXXX_r1.58ff94782d7c325acc49a8dd9c04bb1e
Physloc
Mirrored              N/A

VTD                   vtscsi26
Status                Available
LUN                   0x8200000000000000
Backing device        l02duapofdev_b1.0ee86903d4951ce38a9b691b322ff1d2
Physloc
Mirrored              N/A
[download]

Comment on sprintf to hash Download Code

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Re: sprintf to hash by toolic (Bishop) on Sep 19, 2014 at 18:58 UTC
Use hex and I think you need to re-work your logic... use warnings; use strict; my %lsmapHash; while (<DATA>) { chomp; if (/^vhost/i) { my $vh = (split)[0]; my $clid = (split)[2]; my $cltid = sprintf '%d', hex $clid; $lsmapHash{$vh} = { 'clientID' => $cltid, }; } } use Data::Dumper; $Data::Dumper::Sortkeys=1; print Dumper(\%lsmapHash) +; __DATA__ SVSA Physloc Client Pa +rtition ID --------------- -------------------------------------------- --------- +--------- vhost10 U9117.MMD.218A8B7-V1-C2 0x0000000b VTD vtscsi25 Status Available LUN 0x8100000000000000 Backing device l02duapXXXX_r1.58ff94782d7c325acc49a8dd9c04bb1e Physloc Mirrored N/A VTD vtscsi26 Status Available LUN 0x8200000000000000 Backing device l02duapofdev_b1.0ee86903d4951ce38a9b691b322ff1d2 Physloc Mirrored N/A [download]	[reply] [d/l]
Re: sprintf to hash by ikegami (Patriarch) on Sep 19, 2014 at 18:54 UTC
You want `hex($clid)`. `sprintf "%d"` doesn't convert something that isn't a number into a number. In fact, it does the opposite. It converts numbers into their string representation. Your test snippet is not equivalent because `0x0000000b` doesn't produce the string `0x0000000b` which you have in your actual code. `$ perl -wE'say sprintf "%d", "0x0000000b"' Argument "0x0000000b" isn't numeric in sprintf at -e line 1. 0` [download] Why didn't you mention you were getting an error message?	[reply] [d/l] [select]
Re: sprintf to hash by RonW (Parson) on Sep 19, 2014 at 23:02 UTC
Yes, you do need to use hex to explicitly convert a string containing a hexadecimal value. This is because while the Perl parser can safely infer that the bare word `0x000a` is a numeric constant expressed in hexadecimal because this is an established syntactic rule of the Perl language. However, Perl's run time string-to-number coercion doesn't make assumptions about a string not matching `/^[0-9]/` because a string is just a string. Perl also has oct to handle octal values. However, there there is an important differnece between hex and oct. hex will only try to interpret the string as hexadecimal, skipping a leading '0x' if present. oct, on the other hand, if the string has a leading '0x' (or '0b'), will try to interpret the string as hexadecimal (or binary). Otherwise, it will try octal. Using oct, you can create a simple, dumb converter that will handle decimal, hexadecimal and binary string to number conversion: `sub dhob2num { my $s = shift; if ($s =~ /^0/) { return oct($s); } # Note: should validate the stri +ng return ( 0 + $s ); }` [download] While flexible and useful, this function is dumb because it doesn't validate the string to insure it is a proper number in the radix indicated by the prefix.	[reply] [d/l] [select]