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How can I check if a file exists in Perl?

...mething exists at given path using the -e file-test operator. print "$base_path exists!\n" if -e $base_path; However, this test is probably broader than you intend. The code above will generate output if a plain file exists at that path, but it will also fire for a directory, a named pipe, a syml...
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Calling Java from Python

...thods from your python code as if they were python methods: from py4j.java_gateway import JavaGateway gateway = JavaGateway() # connect to the JVM java_object = gateway.jvm.mypackage.MyClass() # invoke constructor other_object = java_object.doThat() other_object.doThis(1,'ab...
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Making a Simple Ajax call to controller in asp.net mvc

...er, it's Url.Action(actionName, controllerName) – xd6_ Apr 27 '17 at 22:20 1 Not a fan of this, i...
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Open an IO stream from a local file or url

...d be able to call methods like read and readlines. require 'open-uri' file_contents = open('local-file.txt') { |f| f.read } web_contents = open('http://www.stackoverflow.com') {|f| f.read } share | ...
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In Rails, how do you render JSON using a view?

... You should be able to do something like this in your respond_to block: respond_to do |format| format.json render :partial => "users/show.json" end which will render the template in app/views/users/_show.json.erb. ...
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How to cancel/abort jQuery AJAX request?

...dyState which contains the state of the request(UNSENT-0, OPENED-1, HEADERS_RECEIVED-2, LOADING-3 and DONE-4). we can use this to check whether the previous request was completed. $(document).ready( var xhr; var fn = function(){ if(xhr && xhr.readyState != 4){ x...
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How to format a number as percentage in R?

...s pointed out by @DzimitryM, percent() has been "retired" in favor of label_percent(), which is a synonym for the old percent_format() function. label_percent() returns a function, so to use it, you need an extra pair of parentheses. library(scales) x <- c(-1, 0, 0.1, 0.555555, 1, 100) label_pe...
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to_string is not a member of std, says g++ (mingw)

...orking. I copied the exact program from the question. I still get the 'to_string' is not a member of 'std' error. I compiled it as: g++ -std=c++0x -o tostring_test.exe tostring_test.cpp – zam664 Dec 2 '13 at 16:58 ...
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Upgrade Node.js to the latest version on Mac OS

... Because you advice to use sudo. – OZ_ Nov 16 '15 at 20:53 2 This works, but: is ...
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adding x and y axis labels in ggplot2

...You can set the labels with xlab() and ylab(), or make it part of the scale_*.* call. library("Sleuth2") library("ggplot2") ggplot(ex1221, aes(Discharge, Area)) + geom_point(aes(size=NO3)) + scale_size_area() + xlab("My x label") + ylab("My y label") + ggtitle("Weighted Scatterplot of W...