How do i find a file major and minor number


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How do i find a file major and minor number

by mmw (Initiate)

on Dec 07, 2011 at 17:41 UTC ( #942294=perlquestion: print w/ replies, xml )

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

How do i retrieve the major and minor number using File::stat?


#!/usr/bin/perl

use File::Find;

find sub { (-c | -b ) && push(@files,$File::Find::name) } , ("/dev") ;
sub retHash () {
   my ($name, $major, $minor ) = split(",",stat -c '%n,%t,%T' $_`);
   my $return = {name=> $name, major=> hex($major), minor=> hex($minor
+) };
           return $return; } 
@files = map ( &retHash($_) , @files);

foreach $item (@files) {
print "$item->{name} $item->{major} $item->{minor}\n";
}

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Comment on How do i find a file major and minor number
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Re: How do i find a file major and minor number
by johngg (Abbot) on Dec 07, 2011 at 17:55 UTC

Probably something similar to this using lstat or stat.

knoppix@Microknoppix:~$ perl -E '
> $rdev = ( stat q{/dev/zero} )[ 6 ];
> $minor = $rdev % 256;
> $major = int( $rdev / 256 );
> say $rdev;
> say $major;
> say $minor;'
261
1
5
knoppix@Microknoppix:~$ ls -l /dev/zero
crw-rw-rw- 1 root root 1, 5 Dec  7 11:39 /dev/zero
knoppix@Microknoppix:~$ perl -E '
> $rdev = ( stat q{/dev/zram0} )[ 6 ];
> $minor = $rdev % 256;
> $major = int( $rdev / 256 );
> say $rdev;
> say $major;
> say $minor;'
64512
252
0
knoppix@Microknoppix:~$ ls -l /dev/zram0
brw-rw---- 1 root disk 252, 0 Dec  7 11:39 /dev/zram0
knoppix@Microknoppix:~$ 
[download]

I hope this is helpful.

Cheers,

JohnGG

[reply]
[d/l]

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