grab 2 blocks of texts from file

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

Hi perl geniuses :p I'm trying to grab 2 "sections" of text from a file, i use a marker to tell the program where to begin and end at each section.. here is my attempt.

@text1 = ();
@Section = split("\n", $filedata);
foreach (@Section) {

   if (/^#begin/ .. /^#end/) {
      $eval .= "$_\n";
   }
   if (/^#begin2/ .. /^#end2/) {
      push(@text1, $_);
  }

} 

@arrBlock = ();
for ($x=1;$x<@text1-1;$x++) {
push(@arrBlock,$text1[$x]);
}

this seems valid, i can print $arryBlock[index] but i cant do a foreac
+h loop through it? here is  an example file:

#begin
aaa
bbb
ccc
ddd
#end

#begin2
xxx
ccc
bbb
#end2
[download]

now text1 contains the first block of content and arrblock contains the second.. i know i suck at variable names heh

Comment on grab 2 blocks of texts from file Download Code

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Re: grab 2 blocks of texts from file by temporal (Pilgrim) on Apr 12, 2012 at 15:21 UTC
Your code doesn't do what you've specified. Maybe you didn't post all of it? It builds a string into the $eval variable containing the first block of text from your file (including your markers). It then pushes the lines from the second block (including your markers) into @text1. Then it copies @text1 minus your markers over to @arrBlock. So in the end, @arrBlock contains your second block and @text1 contains your second block with the markers... It would probably be more efficient to do an array slice: `@firstblock = @text1[1..($#text1-1)]; # remember the left index of the slice can never be greater than the r +ight... no -1` [download] Not sure what you mean by not being able to do a foreach loop through it: `foreach $value (@arrBlock) { print "$value\n"; }` [download]	[reply] [d/l] [select]
Re: grab 2 blocks of texts from file by graff (Chancellor) on Apr 13, 2012 at 00:16 UTC
Since you seem to be slurping the entire content of the data file into a scalar variable, it might be easier just to use regex matches on that one big string: `if ( $filedata =~ /#begin\n (.?) #end\n .? #begin2\n (.*?) #end2/sx +) { ( $block1, $block2 ) = ( $1, $2 ); @arr_block1 = split /\n/, $block1; @arr_block2 = split /\n/, $block2; }` [download] Recall from your studies of perlre that the "s" modifier allows the "." wildcard to match new-lines as well as all other characters, and "x" allows for using spaces in the regex for legibility (not for matching literal spaces). I chose to match both blocks with one regex, but you could do each block as a separate regex match if you want.	[reply] [d/l]
Re: grab 2 blocks of texts from file by Kenosis (Priest) on Apr 15, 2012 at 00:37 UTC
I like graff's suggestion of using the s modifier in your regex if the file's slurped into $filedata. Given that, here's another solution to grabbing those two sections, and it then places them into an array of arrays `@arrBlocks` (where `$arrBlocks[0]` is an array of the first block's elements and `$arrBlocks[1]` is an array of the second block's elements): `for($filedata =~ /#begin\d?\n(.?)#end\d*?\n/gs) { push @arrBlocks, [split "\n"]; }` [download] The regex matches your pattern and can be used for endless #begin/#end pairs that end with digits (e.g., #begin3/#end3, ...). If you started with #begin0/#end0, then `$arrBlocks[0]` would contain that block's elements. Hope this helps!	[reply] [d/l] [select]