Why isn't this a quine?

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

Replies are listed 'Best First'.
Re: Why isn't this a quine? by plobsing (Friar) on Aug 01, 2009 at 23:54 UTC
It's not a true quine. A true quine generates it's own source. This only finds the file that contains the source and prints it. It also has a race condition: if I replace the file shortly after you've run it, it will output whatever is in the new file and not the source code.	[reply]
Re^2: Why isn't this a quine? by mchampag (Acolyte) on Aug 02, 2009 at 00:03 UTC
Now that's the sort of response I was expecting. So it's not enough to simply print out its code listing; a quine must also generate itself. Very koan-like. Thank you!	[reply]
Re^2: Why isn't this a quine? by JadeNB (Chaplain) on Aug 03, 2009 at 15:33 UTC
A true quine generates it's own source. What does it mean to ‘generate’ source? Unless you mean something subjective like “uses clever or tricky-to-understand mechanisms”, it seems to me that the OP's proposed quine ‘generates’ its source using a call to `system`, which makes a further call to `cat`.	[reply] [d/l] [select]
Re: Why isn't this a quine? by GrandFather (Saint) on Aug 02, 2009 at 00:13 UTC
Perl is not one of the worst languages for generating a quine: `seek DATA, 0, 0; print <DATA> __DATA__` [download] Prints: `seek DATA, 0, 0; print <DATA> __DATA__` [download] True laziness is hard work	[reply] [d/l] [select]
Re^2: Why isn't this a quine? by hossman (Prior) on Aug 02, 2009 at 23:48 UTC
might as well make it psuedo-palandromy `hossman@coaster:~$ cat monk.pl seek DATA, 0, 0; print <DATA> __DATA__ print <DATA> seek DATA, 0, 0; hossman@coaster:~$ perl monk.pl seek DATA, 0, 0; print <DATA> __DATA__ print <DATA> seek DATA, 0, 0;` [download]	[reply] [d/l]
Re: Why isn't this a quine? by eyepopslikeamosquito (Archbishop) on Aug 02, 2009 at 03:56 UTC
See The Quine Page	[reply]
Re: Why isn't this a quine? by dave_the_m (Monsignor) on Aug 02, 2009 at 12:06 UTC
`s zzs vvxv and s ZVZchr 122Zie and s ZVZchr 122Zie and s ZVZchr 122Zie and s SxSlcfirstSe and s YZZxZYvvxvYi and print z and s ZVZchr 122Zie and s ZVZchr 122Zie and s ZVZchr 122Zie and s SxSlcfirstSe and s YZZxZYvvxvYi and print` [download]	[reply] [d/l]
Re^2: Why isn't this a quine? by JadeNB (Chaplain) on Aug 03, 2009 at 15:59 UTC
That's adorable. I thought at first that it was Befunge or some variant—then I wondered about what purpose a command like `s` would serve in a directional language—then enlightenment dawned (though it took me a while to find the third ‘z’).	[reply] [d/l]
Re: Why isn't this a quine? by Anonymous Monk on Aug 01, 2009 at 23:46 UTC
Yes, because it is a computer program which produces a copy of its own source code as its only output.	[reply]
Re^2: Why isn't this a quine? by mchampag (Acolyte) on Aug 01, 2009 at 23:50 UTC
Thank you for your response! I thought it fitted the definition, but every quine I've ever seen seems to be very difficult to understand. As this one is trivially simple, it seems like it should maybe be disqualified. -Matt	[reply]


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