Re: Printing Last Element of a line using perl memory?

A somewhat different way of doing it:

perl -lne 's[\A\s+][]; s[\s+\Z][]; $last=pop [split /\s+/] if $_; END 
+{ print $last }' scan.log
[download]

-l auto-chomps
-n wraps the code in a while(<>){ ... }
The substitutions remove leading and trailing blanks
The split extracts the words in the line (whitespace-separated)
The pop takes the last word
We save this for each line
At end of file, we print the current last word, which will be from the last line

Comment on Re: Printing Last Element of a line using perl memory? Download Code

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Re^2: Printing Last Element of a line using perl memory? by LanX (Saint) on Feb 15, 2013 at 09:42 UTC
> The pop takes the last word Version warning! =) not with < 5.14 `DB<100> $_=join " ",a..z => "a b c d e f g h i j k l m n o p q r s t u v w x y z" DB<101> $x= pop [ split / / ] ;; Type of arg 1 to pop must be array (not anonymous list ([])) at (eval +20)[multi_perl5db.pl:644] line 2, at EOF DB<102> $x= pop @{[ split / / ]} # Workaround => "z"` [download] Cheers Rolf	[reply] [d/l]
Re^3: Printing Last Element of a line using perl memory? by pemungkah (Priest) on Mar 11, 2013 at 19:59 UTC
Thanks! Filing that one.	[reply]
Re^4: Printing Last Element of a line using perl memory? by LanX (Saint) on Mar 11, 2013 at 20:09 UTC
here a way to avoid a temp array `DB<100> $_=join " ",a..z => "a b c d e f g h i j k l m n o p q r s t u v w x y z" DB<101> $x = (split / /)[-1] => "z"` [download] Cheers Rolf	[reply] [d/l]
Re^2: Printing Last Element of a line using perl memory? by jaredor (Priest) on Feb 15, 2013 at 18:12 UTC
++ for the END block idea. A further tweak would be to not process data in the main loop, but only the END block. Unfortunately I could not think of a slick way to make $_ available to END from the last loop iteration, so I had to cheat a little to golf your solution. Apparently the autosplit array does remain resident: `perl -nae 'END { print "$F[-1]\n"; }' scan.log` Good examples like yours are weaning me from sed ;-)	[reply] [d/l]
Re^3: Printing Last Element of a line using perl memory? by pemungkah (Priest) on Mar 11, 2013 at 20:02 UTC
Ooh, nice! I'll use that one too.	[reply]