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Simple one-liners may be specified as command line arguments to perl using the -e switch (think "execute"): perl -e'print "Hello, World!\n"' Due to Windows quoting rules you can't use single-quoted strings but have to use one of these variants: perl -e"print qq(Hello, W...

Windows uses only double quotes to wrap command line parameters. In order to use double quotes in perl one-liner (i.e. to print a string with an interpolated variable), you have to escape them with backslashes: perl -e "my $greeting = 'Hello'; print \"$greeting, world!\n\"" T...

perl -ne'print if /foo/' file.txt Case-insensitive: perl -ne'print if /foo/i' file.txt

perl -pe"s/foo/bar/g" file.txt Or in-place: perl -i -pe's/foo/bar/g' file.txt On Windows: perl -i.bak -pe"s/foo/bar/g" file.txt

perl -lane'print "$F[0] $F[-1]"' data.txt # prints the first and the last fields of a space delimited record CSV example: perl -F, -lane'print "$F[0] $F[-1]"' data.csv

perl -ne'print if 5..10' file.txt

Without a backup copy (not supported on Windows) perl -i -pe's/foo/bar/g' file.txt With a backup copy file.txt.bak perl -i.bak -pe's/foo/bar/g' file.txt With a backup copy old_file.txt.orig in the backup subdirectory (provided the latter exists): perl -i'backup/old_*.orig' -pe's/foo/bar/g' ...

perl -0777 -ne'print "The whole file as a string: --->$_<---\n"' Note: The -0777 is just a convention. Any -0400 and above would de the same.

With XML::Rabbit it is possible to consume XML files easily. You define in a declarative way and with an XPath syntax what you are looking for in the XML and XML::Rabbit will return objects according to the given definition. Definition: package Bookstore; use XML::Rabbit::Root; has_xpath_object_...

It is good practice to test the calling program's __name__ variable before executing your code. import sys def main(): # Your code starts here # Don't forget to provide a return code return 0 if __name__ == "__main__": sys.exit(main()) Using this pattern ens...

Adding components one after another results in a UI that's hard to use, because the components all are somewhere. The components are ordered from top to bottom, each component in a separate "row". To remedy this and provide you as developer with a possibility to layout components easily S...

Weka is a collection of machine learning algorithms for data mining tasks. The algorithms can either be applied directly to a dataset or called from your own Java code. Weka contains tools for data pre-processing, classification, regression, clustering, association rules, and visualization. It is al...

Margin is one of a few CSS properties that can be set to negative values. This property can be used to overlap elements without absolute positioning. div{ display: inline; } #over{ margin-left: -20px; } <div>Base div</div> <div id="over">Overlapping div&lt...

genRandom creates a stream of random numbers that has a one in four chance of terminating each time it's called. def genRandom: Stream[String] = { val random = scala.util.Random.nextFloat() println(s"Random value is: $random") if (random < 0.25) { Stream.empty[String] ...

curl -XGET 'http://www.example.com:9200/myIndexName/_count?pretty' Output: { "count" : 90, "_shards" : { "total" : 6, "successful" : 6, "failed" : 0 } } The index has 90 documents within it. Reference Link: Here

curl -XPUT 'www.example.com:9200/myIndexName?pretty' Output: { "acknowledged" : true } Reference Link: Here

curl 'www.example.com:9200/_cat/indices?v' output: health status index pri rep docs.count docs.deleted store.size pri.store.size green open logstash-2016.07.21 5 1 4760 0 4.8mb 2.4mb green open logstash-2016.07.20 5 1 7232 ...

curl -XDELETE 'http://www.example.com:9200/myIndexName?pretty' output: { "acknowledged" : true } Reference Link: Here

Let's say there's a collection called Todos and the autopublish package is added. Here is the basic component. import { createContainer } from 'meteor/react-meteor-data'; import React, { Component, PropTypes } from 'react'; import Todos from '/imports/collections/Todos'; export class List exte...

If you're going to be designing layouts with fixed size screens for different mobile devices, you may want to mirror that design when running your app on a desktop. The following method fixes the size of the window OUTSIDE of PhoneGap, giving a fixed-sized window on the desktop. Sometimes it's easie...