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Full Discussion: Perl : Large amount of data put into an array
Top Forums Shell Programming and Scripting Perl : Large amount of data put into an array Post 302817403 by MadeInGermany on Wednesday 5th of June 2013 06:41:05 PM
Old 06-05-2013
So many lines - you normally read them from a file!
Then instead of
Code:
open (FH, "<file");
@MYARRAY = <FH>;
foreach $eachline (@MYARRAY) {
   chomp $eachline;
   if ($eachline =~ /\b$ARGV[0]\b/) {
     print "$eachline\n";
   }
}

You save the memory with
Code:
open (FH, "<file");
foreach $eachline (<FH>) {
   chomp $eachline;
   if ($eachline =~ /\b$ARGV[0]\b/) {
     print "$eachline\n";
   }
}

and in this case even save the loop with
Code:
open (FH, "<file");
print grep (/\b$ARGV[0]\b/, <FH>);

 

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LEARN ABOUT PHP

array_unshift

ARRAY_UNSHIFT(3)							 1							  ARRAY_UNSHIFT(3)

array_unshift - Prepend one or more elements to the beginning of an array

SYNOPSIS

       int array_unshift (array  &$array, mixed  $value1, [mixed  $...])

DESCRIPTION

       array_unshift(3)  prepends  passed elements to the front of the $array. Note that the list of elements is prepended as a whole, so that the
       prepended elements stay in the same order. All numerical array keys will be modified to start counting from zero while literal  keys  won't
       be touched.

PARAMETERS

	      o $array
		- The input array.

	      o $value1
		- First value to prepend.

RETURN VALUES

	Returns the new number of elements in the $array.

EXAMPLES

       Example #1

	      array_unshift(3) example

	      <?php
	      $queue = array("orange", "banana");
	      array_unshift($queue, "apple", "raspberry");
	      print_r($queue);
	      ?>

	      The above example will output:

	      Array
	      (
		  [0] => apple
		  [1] => raspberry
		  [2] => orange
		  [3] => banana
	      )

SEE ALSO

       array_shift(3), array_push(3), array_pop(3).

PHP Documentation Group 													  ARRAY_UNSHIFT(3)
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