print to output problem

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

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Re: print to output problem by Joost (Canon) on Jul 07, 2004 at 16:27 UTC
It seems I'm only posting this link today. <-- read that first. What is your input? What do you think the output should be? for each line, you are pushing 1 value into @outLines (so, you're adding one value to the end of the array) and then printing @outLines. That might be the source of your problem. "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply]
Re^2: print to output problem by Anonymous Monk on Jul 07, 2004 at 16:30 UTC
adding one value to the end of the array - this is why i included just after the while(<FILE>) empty the array i am pushing onto?	[reply]
Re^3: print to output problem by Joost (Canon) on Jul 07, 2004 at 16:34 UTC
I think you'll find that # starts a comment. so that line doesn't do anything. Also, generally people will tell you to `use strict;` and `use warnings;` at the top of your code. which might give you some interesting hints. update: I don't think you really understand split either. type `perldoc -f split`, especially this section: `In scalar context, returns the number of fields found a +nd splits into the @_ array. Use of split in scalar conte +xt is deprecated, however, because it clobbers your subroutin +e argu- ments. If EXPR is omitted, splits the $_ string. If PATTERN i +s also omitted, splits on whitespace (after skipping any leadi +ng whitespace). Anything matching PATTERN is taken to be +a delim- iter separating the fields. (Note that the delimiter m +ay be longer than one character.)` [download] "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply] [d/l] [select]
Re^4: print to output problem by Anonymous Monk on Jul 07, 2004 at 16:42 UTC
Re^5: print to output problem by Joost (Canon) on Jul 07, 2004 at 16:47 UTC
Re: print to output problem by sweetblood (Prior) on Jul 07, 2004 at 16:30 UTC
You want the print statement outside of your while loop `push (@outLines, $val); } print OUT @outLines;` [download] Otherwise it print the contents of @outLines for each line HTH Sweetblood	[reply] [d/l]
Re^2: print to output problem by Anonymous Monk on Jul 07, 2004 at 16:36 UTC
i have multiple entries in my input file to look at, so if i was to print outside the while loop, surely i will only be printing the last loop through the input?	[reply]
Re^3: print to output problem by Joost (Canon) on Jul 07, 2004 at 16:39 UTC
Don't guess, read the documentation. "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply]
Re^3: print to output problem by Anonymous Monk on Jul 07, 2004 at 16:40 UTC
here is my input file: `# input for ....find 17th and 18th number # input for .... again Nd RES PDB val 1 140 31 20.0 1 142 33 0.0 1 143 34 10.0 1 144 35 0.0` [download] say 17th number is 143, would print out 10 on first loop then say 17th number is 140 would print 20 on second	[reply] [d/l]
Re: print to output problem by Roy Johnson (Monsignor) on Jul 07, 2004 at 17:20 UTC
Does this do what you want? `while (<FILE>) { undef $val; if (/^# input/) { ($etc) = (split)[1] } elsif (/^\s\s\d+/) { ($space, $Nd, $RES, $PDB, $val) = split } elsif /^\s.$NUM17\b/) { $val = (split)[3] } elsif /^\s.$NUM18\b/) { $va2 = (split)[3] } if (defined $val) { push(@outlines, $val); print $val; } }` [download] We're not really tightening our belts, it just feels that way because we're getting fatter.	[reply] [d/l]
Re^2: print to output problem by Anonymous Monk on Jul 08, 2004 at 10:30 UTC
thanks for the effort Roy but still only prints the last $val?	[reply]
Re^3: print to output problem by Roy Johnson (Monsignor) on Jul 08, 2004 at 13:31 UTC
It looks like you need to store up your $NUM17 values in an array, and you also need to store up your RES-val pairs in a hash. Then, after you've read and stored the whole mess, go through the array and print the corresponding hash values. Like: `my @requests = (); my %lookups = (); while (<FILE>) { if (/^# input/) { push @requests, (split)[1]; } elsif (/^\s\s\d+/) { my ($RES, $val) = (split)[2,4] $lookups{$RES} = $val; } } print join("\n", @lookups{@requests}), "\n";` [download] It's not clear to me what the $NUM17 and $NUM18 business is all about, or what $etc is for. What I've done is assume that $etc indicates which $RES to look for, to print the associated $val. We're not really tightening our belts, it just feels that way because we're getting fatter.	[reply] [d/l]
Re: print to output problem by dws (Chancellor) on Jul 07, 2004 at 16:46 UTC
If you really intend to discard part of the result of a split, it's clearer to write `(undef, $etc) = split(/\s+/, $_) if (/^# input./);` [download] than to write `($etc,$etc) = split (/\s+/, $_) if (/^# input./);` [download]	[reply] [d/l] [select]
Re^2: print to output problem by Anonymous Monk on Jul 07, 2004 at 16:50 UTC
i know it returning the correct value by using `print OUT (split)[3], "\n" if /^\s+\S+\s+\S+\s+$NUM17\b/;` [download] its just the fact that the out puts are all strings of the same answer	[reply] [d/l]
Re: print to output problem by Roy Johnson (Monsignor) on Jul 07, 2004 at 16:52 UTC
You just want to print $val within the loop. We're not really tightening our belts, it just feels that way because we're getting fatter.	[reply]
Re: print to output problem by gellyfish (Monsignor) on Jul 07, 2004 at 16:59 UTC
The only times $val is assigned to it is conditional upon the input and at no point are you resetting the value of $val, therefore if the first line matches and no further lines do then $val will retain the same value and @outlines will be populated with identical values. /J\	[reply]
Re^2: print to output problem by Anonymous Monk on Jul 07, 2004 at 17:08 UTC
also tried this ealrier on along with cleaning the @outLines oout, but still returns the last output only	[reply]
Re: print to output problem by Anonymous Monk on Jul 07, 2004 at 16:21 UTC
#@outLines = (); no hash!	[reply]