Re^3: Golf: reverse sort /etc/passwd by UID

D'oh! I did omit a couple of bits didn't I (It was (obviously) untested -- I don't have an /etc/passwd).

I tried to remove the $b=~ & $a=~ bits when I noticed that reverse was one character less -- ignoring/forgetting that $_ cannot be both at the same time :(.

I don't think the (...)[0] bits are necessary, without /g only the regex will only return one (the first) match.

This should work? (still untested):

perl -E"say sort{$b=~/:(\d+):/<=>$a=~/:(\d+):/}<>" /etc/passwd
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Re^4: Golf: reverse sort /etc/passwd by UID by thundergnat (Deacon) on Feb 05, 2013 at 20:33 UTC
No, unfortunately that doesn't work either. A regex match in scalar context returns 1 or 0. It needs to be called in list context to return the value. `>perl -E"print 'foo'=~/(o+)/;" oo` [download] `>perl -E"print scalar 'foo'=~/(o+)/;" 1` [download]	[reply] [d/l] [select]
Re^4: Golf: reverse sort /etc/passwd by UID by Tommy (Chaplain) on Feb 05, 2013 at 20:26 UTC
~~No, no. It does work (tested and confirmed). See my reply to thundergnat.~~ ~~NOTE- remember you have to omit the typos though, as I already pointed out. So far, the winner remains:~~ UPDATE: thundergnat is right that the code below DOESN'T work as intended `perl -e 'print reverse sort{/(:\d+:)/<=>/(:\d+:)/}<>' /etc/passwd` Tommy A mistake can be valuable or costly, depending on how faithfully you pursue correction	[reply] [d/l]
Re^5: Golf: reverse sort /etc/passwd by UID by thundergnat (Deacon) on Feb 05, 2013 at 20:40 UTC
No, no. It doesn't work (tested and confirmed). The sort block operates on the global variables $a and $b. A match without an explicit variable operates on $_. There is nothing mapping $a and $b to $_ there, so the sort block is just comparing 0 to 0 and leaving the order alone. The fact that /etc/password is in a "sorted" order makes it SEEM like it is working... but it isn't. `print reverse sort{/(:\d+:)/<=>/(:\d+:)/}<DATA>; __DATA__ aaa:5: bbb:3: ccc:1: ddd:7: eee:8:` [download] eee:8: ddd:7: ccc:1: bbb:3: aaa:5:	[reply] [d/l]