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What is the difference between the | and || or operators?
...th in C# and PHP. Occasionally I see a single pipe used: | . What is the difference between those two usages? Are there any caveats when using one over the other or are they interchangeable?
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Is it possible only to declare a variable without assigning any value in Python?
...oesn't mean that you won't end up with incorrectly initialized variables. If you init something to None, make sure that's what you really want, and assign something more meaningful if you can.
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Check if a file exists with wildcard in shell script [duplicate]
I'm trying to check if a file exists, but with a wildcard. Here is my example:
21 Answers
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How to make “if not true condition”?
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try
if ! grep -q sysa /etc/passwd ; then
grep returns true if it finds the search target, and false if it doesn't.
So NOT false == true.
if evaluation in shells are designed to be very flexible, and many times doesn't require...
Checking from shell script if a directory contains files
From a shell script, how do I check if a directory contains files?
26 Answers
26
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How to detect Windows 64-bit platform with .NET?
...onment.Is64BitOperatingSystem.
IntPtr.Size won't return the correct value if running in 32-bit .NET Framework 2.0 on 64-bit Windows (it would return 32-bit).
As Microsoft's Raymond Chen describes, you have to first check if running in a 64-bit process (I think in .NET you can do so by checking IntP...
Checking if sys.argv[x] is defined
What would be the best way to check if a variable was passed along for the script:
8 Answers
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Is the ternary operator faster than an “if” condition in Java [duplicate]
I am prone to " if-conditional syndrome " which means I tend to use if conditions all the time. I rarely ever use the ternary operator. For instance:
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How to exit if a command failed?
...am a noob in shell-scripting. I want to print a message and exit my script if a command fails. I've tried:
8 Answers
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How to know if user is logged in with passport.js?
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If user is logged in, passport.js will create user object in req for every request in express.js, which you can check for existence in any middleware:
if (req.user) {
// logged in
} else {
// not logged in
}
You ca...