> Now, does anyone have a simpler way than using the ".map" above?
There were a few in the thread!
Here's my golfing, unlike the others, this preserves the order of the lines
(which may or may not be desired)
raku -ne '.say if $++ == any 6,3,1' line0-10.txt
-y
On Tue, Aug 25, 2020 at 12:03 PM William Michels via perl6-users <
perl6-us...@perl.org> wrote:
> If Todd wants to print lines containing "Line 1", "Line 3", and "Line 7",
> he's going to have to correct for zero-indexing:
>
> user@book:~$ raku -e '$*IN.lines[ 1,3,7 ].join("\n").put;' < Lines.txt
> Line 2
> Line 4
> Line 8
>
> #Below: subtracting one from (1,3,7) gives the return he wants:
>
> user@book:~$ raku -e '$*IN.lines[ (1,3,7).map: { $_ - 1 }
> ].join("\n").put;' < Lines.txt
> Line 1
> Line 3
> Line 7
>
> Now, does anyone have a simpler way than using the ".map" above?
>
> HTH, Bill.
>
>
>
> On Tue, Aug 25, 2020 at 10:46 AM Andy Bach <andy_b...@wiwb.uscourts.gov>
> wrote:
>
>> Ah, I see, the -n reads a line and then my lines on $*IN starts with the
>> next one
>> C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe" -e "my
>> @x = $*IN.lines(); say @x[0,1,7,3]; "
>> (Line 0 Line 1 Line 7 Line 3)
>>
>> and so $*IN is the default for lines()
>> C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe" -e "my
>> @x = lines(); say @x[0,1,7,3]; "
>> (Line 0 Line 1 Line 7 Line 3)
>>
>> This hangs, with and without the -n
>> C:\> "\Program Files (x86)\rakudo\bin\raku.exe" -ne "my @x =
>> $*IN.lines(); say @x[0,1,7,3]; " lines.txt
>>
>> Though:
>> C:\> "\Program Files (x86)\rakudo\bin\raku.exe" -ne "my @x = lines();
>> say @x[0,1,7,3]; " lines.txt
>> (Line 1 Line 2 Line 8 Line 4)
>> Cannot do 'get' on a handle in binary mode
>> in block <unit> at -e line 1
>>
>> a
>>
>> Andy Bach, BS, MSCMECFA
>> Systems Mangler
>> Internet: andy_b...@wiwb.uscourts.gov
>> Voice: (608) 261-5738, Cell: (608) 658-1890
>>
>> "The three great problems of computer science:
>> compiler complexity and 'off-by-one' errors".
>> https://martinfowler.com/bliki/TwoHardThings.html
>>
>> ------------------------------
>> *From:* Andy Bach <andy_b...@wiwb.uscourts.gov>
>> *Sent:* Tuesday, August 25, 2020 12:18 PM
>> *To:* Parrot Raiser <1parr...@gmail.com>
>> *Cc:* perl6-users <perl6-us...@perl.org>; ToddAndMargo <
>> toddandma...@zoho.com>
>> *Subject:* Re: print particular lines question
>>
>> On Win10
>> C:\>type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe" -ne
>> "say lines()[1,7,3]; "
>> (Line 2 Line 8 Line 4)
>> (Line 11 Nil Nil)
>>
>> C:\>type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe" -ne
>> "say lines()[1,7,3].join(qq~\n~); "
>> Line 2
>> Line 8
>> Line 4
>> Use of Nil in string context
>> in block at -e line 1
>> Use of Nil in string context
>> in block at -e line 1
>> Line 11
>>
>> and, speaking of that off by one problem ... lines.txt does start with
>> "line 0"
>> C:\> type lines.txt | "\Program Files (x86)\rakudo\bin\raku.exe" -ne
>> "my @x = $*IN.lines(); say @x[0,1,7,3]; "
>> (Line 1 Line 2 Line 8 Line 4)
>>
>> a
>>
>> Andy Bach, BS, MSCMECFA
>> Systems Mangler
>> Internet: andy_b...@wiwb.uscourts.gov
>> Voice: (608) 261-5738, Cell: (608) 658-1890
>>
>> "The three great problems of computer science:
>> compiler complexity and 'off-by-one' errors".
>> https://martinfowler.com/bliki/TwoHardThings.html
>>
>> ------------------------------
>> *From:* Parrot Raiser <1parr...@gmail.com>
>> *Sent:* Tuesday, August 25, 2020 11:22 AM
>> *To:* Andy Bach <andy_b...@wiwb.uscourts.gov>
>> *Cc:* perl6-users <perl6-us...@perl.org>; ToddAndMargo <
>> toddandma...@zoho.com>
>> *Subject:* Re: print particular lines question
>>
>> That will golf a little (and improve it) to:
>>
>> $ raku -e '.say for lines()[3,2,5]' lines.txt
>>
>> but you have to remember that it's zero-based. I used the first sample
>> file and got
>> Line 4
>> Line 3
>> Line 6
>>
>> "The three great problems of computer science: compiler complexity and
>> 'off-by-one' errors".
>>
>>
>> On 8/25/20, Andy Bach <andy_b...@wiwb.uscourts.gov> wrote:
>> >> Assigning `my @x=$_.lines` puts everything into $x[0]
>> >
>> > Trying this on windows
>> >
>> > C:\> raku.exe -e "my @x = 'lines.txt'.IO.lines; say
>> > @x[1,7,3].join(qq~\n~); "
>> > Line 1
>> > Line 7
>> > Line 3
>> >
>> > or
>> > C:\> raku.exe -e " say 'lines.txt'.IO.lines[1,7,3].join(qq~\n~); "
>> > Line 1
>> > Line 7
>> > Line 3
>> >
>> > a
>> >
>> > Andy Bach, BS, MSCMECFA
>> > Systems Mangler
>> > Internet: andy_b...@wiwb.uscourts.gov<mailto:
>> andy_b...@wiwb.uscourts.gov>
>> > Voice: (608) 261-5738, Cell: (608) 658-1890
>> >
>> > Every man has the right to an opinion but no man
>> > has a right to be wrong in his facts. Nor, above all,
>> > to persist in errors as to facts. Bernard Baruch
>> >
>> > ________________________________
>> > From: ToddAndMargo via perl6-users <perl6-us...@perl.org>
>> > Sent: Monday, August 24, 2020 9:35 PM
>> > To: perl6-users <perl6-us...@perl.org>
>> > Subject: print particular lines question
>> >
>> > Hi All,
>> >
>> > I seems I should know how to do this, but
>> > I am drawing a blank.
>> >
>> > $ cat Lines.txt | raku -ne 'say $_;'
>> > Line 1
>> > Line 2
>> > Line 3
>> > Line 4
>> > Line 5
>> > Line 6
>> > Line 7
>> > Line 8
>> > Line 9
>> > Line 10
>> > Line 11
>> >
>> >
>> > I want to print liens 1, 3, and 7.
>> >
>> > Assigning `my @x=$_.lines` puts everything into $x[0]
>> >
>> >
>> > Many thanks,
>> > -T
>> >
>>
>
