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From: Ilya Zakharevich on 26 Jun 2010 02:16 On 2010-06-26, C.DeRykus <derykus(a)gmail.com> wrote: > () = <>; Try to do it with a terabyte file... Yours, Ilya
From: John Kelly on 26 Jun 2010 02:48 On Fri, 25 Jun 2010 22:08:54 -0700 (PDT), "C.DeRykus" <derykus(a)gmail.com> wrote: >> > � �my $data; >> > � �while (<>) { >> > � � � �chomp; >> > � � � �length or next; >> > � � � �$data = $_; >> > � � � �last; >> > � �} >> > � �{ >> > � � � �local $/ = \2048; >> > � � � �1 while <>; >> > � �} >> >> >Ben >> >> That looks interesting, �I get the first part, the rest will give me >> something to chew on ... >> > >But, this'll just read/toss 2048 byte chunks >till EOF. Alternatively, if you want to toss >the entire stream after exiting the loop, a >single statement: > > <>; > >does what you want due to the list context. I >suspect there's little to gain by changing $/. That doesn't look like list context to me. Testing a small data set containing: > > > >one >two > >three > >four > with this code: ----------------------- #!/usr/bin/perl use strict; use warnings; my $data = ''; while (<>) { chomp; /^\s*$/ and next; $data = $_; print "data=\"$data\"\n"; last; } <> or die "1 EOF\n"; <> or die "2 EOF\n"; <> or die "3 EOF\n"; <> or die "4 EOF\n"; <> or die "5 EOF\n"; <> or die "6 EOF\n"; <> or die "7 EOF\n"; <> or die "8 EOF\n"; <> or die "9 EOF\n"; close STDIN; -------------------------------- produces output: >data="one" >6 EOF Which seems to prove that a bare <> is scalar context. -- Web mail, POP3, and SMTP http://www.beewyz.com/freeaccounts.php
From: C.DeRykus on 26 Jun 2010 02:53 On Jun 25, 11:16 pm, Ilya Zakharevich <nospam-ab...(a)ilyaz.org> wrote: > On 2010-06-26, C.DeRykus <dery...(a)gmail.com> wrote: > > > () = <>; > > Try to do it with a terabyte file... > Hm, sounds like I need to look more closely... So a humongous temp array gets built with only the resulting assignment being optimized away...? -- Charles DeRykus perl -MO=Concise -e "()=<>" 8 <@> leave[1 ref] vKP/REFC ->(end) 1 <0> enter ->2 2 <;> nextstate(main 1 -e:1) v:{ ->3 7 <2> aassign[t3] vKS ->8 - <1> ex-list lK ->6 3 <0> pushmark s ->4 5 <1> readline[t2] lK/1 ->6 4 <#> gv[*ARGV] s ->5 - <1> ex-list lK ->7 6 <0> pushmark s ->7 - <0> stub lPRM* ->-
From: John Kelly on 26 Jun 2010 02:53 On Sat, 26 Jun 2010 06:16:29 +0000 (UTC), Ilya Zakharevich <nospam-abuse(a)ilyaz.org> wrote: >On 2010-06-26, C.DeRykus <derykus(a)gmail.com> wrote: >> () = <>; > >Try to do it with a terabyte file... Aim gun at foot. Pull trigger. Not my concept of fun. -- Web mail, POP3, and SMTP http://www.beewyz.com/freeaccounts.php
From: John Kelly on 26 Jun 2010 03:22
Thanks for the ideas, wrong ones too. They taught me more Perl, and got me pointed in the right direction. -- Web mail, POP3, and SMTP http://www.beewyz.com/freeaccounts.php |