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

Hi - I'm wondering if there's a perl functional equivalent of this specific C implementation of memset? In this case, STN_NAME_LEN is equal to "5". Thank you.

memset(stn_names[recordCount], 0, STN_NAME_LEN);

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Re: Perl memset equivalent?
by moritz (Cardinal) on Jun 26, 2012 at 18:37 UTC

    You don't have direct memory access in Perl, so talking about an equivalent is a bit misleading.

    If you want to set a range of array elements to zero, you can do that as 

    @array[0..4] = (0) x 5;

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    If you want to create a string of zero-bytes, you can write 

    my $s = "\0" x 5;

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    (Update: fixed off-by-one error noticed by martin++).

    Perl 6 - the future is here, just unevenly distributed
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Re: Perl memset equivalent?
by BrowserUk (Patriarch) on Jun 26, 2012 at 18:37 UTC

    Ostensibly:

    use constant STN_NAME_LEN => 5;

$stn_names[ $recordCount ] = chr(0) x STN_NAME_LEN;

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    But there is bound to be more behind this question than you are telling us.

    With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
    Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
    "Science is about questioning the status quo. Questioning authority".
    In the absence of evidence, opinion is indistinguishable from prejudice.

    The start of some sanity?
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Re: Perl memset equivalent?
by sauoq (Abbot) on Jun 26, 2012 at 18:43 UTC

    It's hard to guess what you are trying to achieve exactly... Do you want: 

    @stn_names = (0) x STN_NAME_LEN;

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    which gives you an array filled with five zeros? Or do you want something more like: 
    my $s = pack "c5", (0)x5;

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    which will give you a string packed with 5 nulls?

    -sauoq
    "My two cents aren't worth a dime.";
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Re: Perl memset equivalent?
by Anonymous Monk on Jun 27, 2012 at 00:18 UTC
    C has no "smart" or particularly "clever" data structures; nothing like a hash or what Perl refers-to as an array. When you look at an existing C program, study what it does ... not how it does it. The choices that a programmer must make when using one language are partly dependent on the task and mostly dependent on the language. The only things that should carry-forward in a reimplementation project are the tasks to be performed, not how it is being done by the program that is being replaced.
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