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Meaning of $? (dollar question mark) in shell scripts
...
This is the exit status of the last executed command.
For example the command true always returns a status of 0 and false always returns a status of 1:
true
echo $? # echoes 0
false
echo $? # echoes 1
From the manual: (acessible by calling man bash in your shell)
$?...
jQuery Ajax File Upload
...t that long any more because all IE only has a 22% world wide market share and 27% in the U.S. and dropping fast. Chances are it is people over 70 years old. So rather then IE dictating what developers have to do IE will either have to shape up or get out of the race.
– Drew Ca...
UIView frame, bounds and center
...to add more correct content.
First a recap on the question: frame, bounds and center and theirs relationships.
Frame A view's frame (CGRect) is the position of its rectangle in the superview's coordinate system. By default it starts at the top left.
Bounds A view's bounds (CGRect) expresses a vie...
What does `kill -0 $pid` in a shell script do?
... 0 to a given PID just checks if any process with the given PID is running and you have the permission to send a signal to it.
For more information see the following manpages:
kill(1)
$ man 1 kill
...
If sig is 0, then no signal is sent, but error checking is still performed.
...
kill(2)
$ man...
List of installed gems?
...
The Gem command is included with Ruby 1.9+ now, and is a standard addition to Ruby pre-1.9.
require 'rubygems'
name = /^/i
dep = Gem::Dependency.new(name, Gem::Requirement.default)
specs = Gem.source_index.search(dep)
puts specs[0..5]....
How can I make setuptools install a package that's not on PyPI?
I've just started working with setuptools and virtualenv. My package requires the latest python-gearman that is only available from GitHub. The python-gearman version that's on PyPI is an old one. The Github source is setuptools-compatible, i.e. has setup.py, etc. Is there a way to make setuptools d...
How do I set cell value to Date and apply default Excel date format?
...requirement to create entire .xls files in-memory (still using Apache POI) and then write them to a file at the end. The only problem standing in my way is the handling of cells with dates.
...
Matplotlib different size subplots
... as wide as the second (same height). I accomplished this using GridSpec and the colspan argument but I would like to do this using figure so I can save to PDF. I can adjust the first figure using the figsize argument in the constructor, but how do I change the size of the second plot?
...
How do I find out if first character of a string is a number?
...s, you must first be sure that the string isn't empty. If it is, charAt(0) and substring(0, 1) will throw a StringIndexOutOfBoundsException. startsWith does not have this problem.
To make the entire condition one line and avoid length checks, you can alter the regexes to the following:
s.matches("...
Define a lambda expression that raises an Exception
...ption without defining a named function. All you need is a strong stomach (and 2.x for the given code):
type(lambda:0)(type((lambda:0).func_code)(
1,1,1,67,'|\0\0\202\1\0',(),(),('x',),'','',1,''),{}
)(Exception())
And a python3 strong stomach solution:
type(lambda: 0)(type((lambda: 0).__code_...