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How to tell if a string is not defined in a Bash shell script

... not set, you can use: if [ -z "${VAR+xxx}" ]; then echo VAR is not set at all; fi if [ -z "$VAR" ] && [ "${VAR+xxx}" = "xxx" ]; then echo VAR is set but empty; fi You probably can combine the two tests on the second line into one with: if [ -z "$VAR" -a "${VAR+xxx}" = "xxx" ]; then echo VA...
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Get name of current class?

... obj.__class__.__name__ will get you any objects name, so you can do this: class Clazz(): def getName(self): return self.__class__.__name__ Usage: >>> c = Clazz() >>> c.getName() 'Clazz' ...
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Simple Log to File example for django 1.3+

...ogfile'], 'level': 'DEBUG', }, } } Now what does all of this mean? Formaters I like it to come out as the same style as ./manage.py runserver Handlers - I want two logs - a debug text file, and an info console. This allows me to really dig in (if needed) and look at a te...
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How to leave a message for a github.com user

...ut the author of the change or the one who accepted it. Provided you're really dying to exchange with user user_test Display the public activity page of the user: https://github.com/user_test?tab=activity Search for an event stating "user_test pushed to [branch] at [repository]". There are usuall...
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How to make graphics with transparent background in R using ggplot2?

...# for the inside of the boxplot ) Fastest way is using using rect, as all the rectangle elements inherit from rect: p <- p + theme( rect = element_rect(fill = "transparent") # all rectangles ) p More controlled way is to use options of theme: p <- p + theme( ...
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When to use Comparable and Comparator

... | Comparable | Comparator ._______________________________________________________________________________ Is used to allow Collections.sort to work | yes | yes Can compare multiple fields | yes ...
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Redirecting to URL in Flask

...eturn a redirect: import os from flask import Flask,redirect app = Flask(__name__) @app.route('/') def hello(): return redirect("http://www.example.com", code=302) if __name__ == '__main__': # Bind to PORT if defined, otherwise default to 5000. port = int(os.environ.get('PORT', 5000)...
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git cherry-pick says “…38c74d is a merge but no -m option was given”

...rticular situation, but using git merge instead of git cherry-pick is generally advisable. When you cherry-pick a merge commit, it collapses all the changes made in the parent you didn't specify to -m into that one commit. You lose all their history, and glom together all their diffs. Your call. ...
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ASP.NET Web API - PUT & DELETE Verbs Not Allowed - IIS 8

...tly upgraded from Visual Studio 2010 to the Visual Studio 2012 RC. The installer also installs IIS 8 Express which Visual Studio now uses as the default web server. ...
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Check for installed packages before running install.packages() [duplicate]

...h several users on different computers. One of its lines contains the install.packages("xtable") command. 16 Answers ...