in reply to using glob to get files

The following works: 

  #! /usr/bin/perl -w
  use strict;

  foreach (glob "$ENV{HOME}/DATA/*.db")
  {
    process_file ($_);
  }

[download]

Please note that calling process_file() with that leading ampersand has side-effects that really surprised me when I first learnt of them.

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Re: Re: using glob to get files
by Anomynous Monk (Scribe) on Mar 12, 2004 at 18:04 UTC
    If you are depending on the side-effects of not having the leading ampersand, you may be in for some surprises, too. Care to share more about your experiences with the evil ampersand?
[reply]

      To quote the good book (Camel, 2nd ed., p115) almost verbatim: 

      &foo(1,2,3);  # pass three arguments.
foo(1,2,3);   # the same.

foo();        # pass a null list.
&foo();       # the same.

&foo;         # foo() gets current args, like foo(@_) !!
foo;          # like foo() IFF sub foo pre-declared, else bareword "fo
+o".

      [download]

      The ampersand also disables any prototype checking on arguments not provided.

      Which means that under certain circumstances, using the ampersand can lead to unexpected results, so in my case, I tend to avoid it in all sub calls, so I don't have to remember the details.

      But I never called it evil, I just wanted folks to be aware that putting an ampersand in front of a sub call has odd behavior when no explicit arguments are passed. when I first read the Camel book, this section made me cringe.

[reply]
[d/l]
        The ampersand also disables any prototype checking on arguments not provided.
        Good. And it gets rid of that pesky "called too early to check prototype" message.

        (That is to say, prototypes are better completely forgotten about. Use them if and when they are actually needed.)

        &foo;
        Don't Do That, Then.
[reply]

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