adding a column of integers

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

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Re: adding a column of integers by borisz (Canon) on Sep 02, 2004 at 13:23 UTC
Whats wrong with your solution? Here is my one: `perl -ple '$_=$s+=$_'` [download] Boris	[reply] [d/l]
Re: adding a column of integers by ccn (Vicar) on Sep 02, 2004 at 13:28 UTC
`perl -lne "$sum+=$_}{print $sum"`	[reply] [d/l]
Re^2: adding a column of integers by Eimi Metamorphoumai (Deacon) on Sep 02, 2004 at 14:19 UTC
Or more verbose, but more understandable (without delving into the actual expansion of -n) `perl -lne '$sum+=$_; END{print $sum}'` [download] The `END` block is executed after everything else. You can also use a corresponding `BEGIN` block before anything else runs, and there are others (`CHECK` and `INIT`, having to do with compile time) for fancy stuff.	[reply] [d/l] [select]
Re^2: adding a column of integers by Smylers (Pilgrim) on Sep 02, 2004 at 16:10 UTC
If you're in the mood for doing sneaky tricks with `-n` then why not be really sneaky: `perl -lne '$;+=$_}{print$'` Smylers	[reply] [d/l] [select]
Re^3: adding a column of integers by Anonymous Monk on Sep 02, 2004 at 21:19 UTC
`perl -lpe '$-+=$_}{$_+=$-}{'` [download]	[reply] [d/l]
Re^4: adding a column of integers by Smylers (Pilgrim) on Sep 03, 2004 at 08:31 UTC
Re^2: adding a column of integers by Random_Walk (Prior) on Sep 02, 2004 at 15:51 UTC
update - whoops I just saw his tail -1 at the end, he is looking for a final total not a running one, DOH!. So option 2 below works just fine Original dumb post This does not work for me, is this my old perl (5.005_03) or am I doing something wrong ? If I add a continue it will work. Here is some output, I have added the > before the numbers I entered just for clarity. `:perl -lne "$sum+=$_}{print $sum" syntax error at -e line 1, near "+=" Execution of -e aborted due to compilation errors. :perl -lne '$sum+=$_}{print $sum' >1 >2 >3 :perl -lne '$sum+=$_}continue{print $sum' >1 1 >2 3 >3 6 >4 10` [download] Cheers, R.	[reply] [d/l]
Re: adding a column of integers by sleepingsquirrel (Chaplain) on Sep 02, 2004 at 14:52 UTC
Choose from solutions in 47 different languages. -- All code is 100% tested and functional unless otherwise noted.	[reply]
Re: adding a column of integers by kscaldef (Pilgrim) on Sep 02, 2004 at 16:14 UTC
`perl -MList::Util=sum -le 'print sum <>'`	[reply] [d/l]
Re: adding a column of integers by sintadil (Pilgrim) on Sep 02, 2004 at 18:14 UTC
`perl -le 'map{$total += $_} <>; print $total'`	[reply] [d/l]
Re^2: adding a column of integers by sintadil (Pilgrim) on Sep 02, 2004 at 18:16 UTC
Note that this uses map in void context, which is bad except in newer Perls. It's not so horrible for a one-liner, though.	[reply]
Re^3: adding a column of integers by Anonymous Monk on Sep 02, 2004 at 21:31 UTC
My, my, my. Another fool who thinks he can appear to be smart by chiming the familiar song about map in void context. And to be really smart he mentions it's not so bad in modern perl. Forget about the map. The damage is done before the map is called. Executing `<>` in list context is slurping in the entire file. You've lost your constant memory solution right there. Regardless of the version of Perl you are using.	[reply] [d/l]
Re^3: adding a column of integers by cog (Parson) on Oct 04, 2004 at 13:35 UTC
I would use a grep instead of a map... :-)	[reply]
Re: --- adding a column of integers by Anonymous Monk on Sep 02, 2004 at 14:34 UTC
`awk '{s += $0} END {print s}' perl -le '$"="+"; print eval "@{[<>]}"'` [download]	[reply] [d/l]
Re^2: --- adding a column of integers by ambrus (Abbot) on Sep 03, 2004 at 20:35 UTC
awk '{s += $0} END {print s}' Also `(echo 0;sed s,$,+, inputfile;echo p)\|dc` [download] or even (with gnu sed) `sed ' G s/^ $[0-9]$ \n$[0-9]$$/0\1pm0\2nb0/;td;d; :d;s/n$\(b$.0\\|\)[^0]$/nb98765432109876543210a0123456789\2/; s/$.$$p.$$.$$n.\1$.a.\3/\2\4\3/; s/^0$.$p$.m$0$.$$.$.\{11\}$/0\1p\4\20\3/; /m0n.0/!bd; s/^$.$p$.$m./\1\2/;s/^0//; h;$!d ' inputfile` [download] but the point of the OP was to improve his Perl* skills. Update 2007 dec 6: see also Re: Golf: Adding up array elements	[reply] [d/l] [select]
Re: adding a column of integers by ambrus (Abbot) on Jun 26, 2006 at 18:25 UTC
This ruby solution also deserves a mention as it doesn't slurp the file thanks to ruby iterators. `ruby -we 'puts $<.inject(0) {\|a, x\| a + x.to_i };'` [download]	[reply] [d/l]
Re^2: adding a column of integers by ikegami (Patriarch) on Jun 26, 2006 at 18:30 UTC
`perl -lne '$sum+=$_; END{print $sum}'` and `perl -le '$sum+=$_ while <>; print $sum'` don't slurp either. `<>` is an iterator (in scalar context).	[reply] [d/l] [select]


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adding a column of integers

update - whoops

Original dumb post