What is a good practice to check if an environmental variable exists or not?
I want to check my environment for the existence of a variable, say “FOO”, in Python. For this purpose, I am using the … Read more
I want to check my environment for the existence of a variable, say “FOO”, in Python. For this purpose, I am using the … Read more
I’m new to bash and I’m stuck at trying to negate the following command: wget -q –tries=10 –timeout=20 –spider http://google.com if [[ $? … Read more
Can the mutate be used when the mutation is conditional (depending on the values of certain column values)? This example helps showing what … Read more
I’ve been thinking of some beginner mistakes and I ended up with the one on the if statement. I expanded a bit the … Read more
I’ve seen Bash scripts test for a non-zero length string in two different ways. Most scripts use the -n option: #!/bin/bash # With … Read more
I have a method that calls 4 other methods in sequence to check for specific conditions, and returns immediately (not checking the following … Read more
I have a string that I load throughout my application, and it changes from numbers to letters and such. I have a simple … Read more
I was reading Java’s ArrayList source code and noticed some comparisons in if-statements. In Java 7, the method grow(int) uses if (newCapacity – … Read more
So far whenever I needed to use a conditional statement within a Widget I have done the following (Using Center and Containers as … Read more
I couldn’t find any one simple straightforward resource spelling out the meaning of and fix for the following BASH shell error, so I’m … Read more