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How to get the last character of a string in a shell?
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101
That's one of the reasons why you need to quote your variables:
echo "${str:$i:1}"
Otherwise, ...
Imitating a blink tag with CSS3 animations
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The original Netscape <blink> had an 80% duty cycle. This comes pretty close, although the real <blink> only affects text:
.blink {
animation: blink-animation 1s steps(5, start) infinite;
-webkit-animation: blink-animation 1s steps(5, start) infi...
Remove columns from dataframe where ALL values are NA
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160
Try this:
df <- df[,colSums(is.na(df))<nrow(df)]
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How can I scan barcodes on iOS?
...ial C++ port of the core library. The port is a little old, from circa the 0.9 release of the Java code, but should still work reasonably well.
If you need to scan other formats, like 1D formats, you could continue the port of the Java code within this project to C++.
EDIT: Barcodes and the iphone...
Java ArrayList how to add elements at the beginning
... beginning of the array (so it has the lowest index) and if the array has 10 elements adding a new results in deleting the oldest element (the one with the highest index).
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Determine if a function exists in bash
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answered Sep 17 '08 at 18:00
JBBJBB
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Difference between Dictionary and Hashtable [duplicate]
...ing (and compile-time verification)
use without boxing
If you are .NET 2.0 or above, you should prefer Dictionary<TKey,TValue> (and the other generic collections)
A subtle but important difference is that Hashtable supports multiple reader threads with a single writer thread, while Dictiona...
Importing a Maven project into Eclipse from Git
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103
+50
Eclipse ...
bundle install fails with SSL certificate verification error
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WillWill
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How to draw a circle with text in the middle?
...enter the text vertically. In this example the height and line-height are 500px.
Example
JSFiddle
.circle {
width: 500px;
height: 500px;
line-height: 500px;
border-radius: 50%;
font-size: 50px;
color: #fff;
text-align: center;
background: #000
}
<div class="circle">Hello I...