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fileperlstat

How's stat function used in Perl?

Can anyone help me to understand the meaning of below line?

#!/usr/bin/perl

use File::stat;

...

sub rootdev { return (stat readlink)[0] == (stat "/")[0]; }
my @vols = shuffle map {/.*\/([0-9]+)/} grep {not rootdev} grep {-e readlink} grep {-l} glob("/dev/shm/v/*");

...

There is submodule like above, but I cannot understand the meaning of stat readlink)[0] == (stat "/")[0].

Solution

  • I got the answer.

    The input of the submodule rootdev is grep {-e readlink} grep {-l} glob("/dev/shm/v/*") .

    So, firstly get the filelist from /dev/shm/v/ directory and filter with grep only for symlink.

    Then check the device id(first array info of stat function) and compare it with root device.

    It's for checking the pointed device of symlink in /dev/shm/v is root device or not to include or exclude whatever.