If it is right that working with environment variables is slower than with ordinary variables (in scripting languages?) then how it is explained?
If it is right that working with environment variables is slower than with ordinary
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If it is right that working with environment variables is slower than with ordinary variables (in scripting languages?) then how it is explained?
Retrieving the value of an environment variable will incur a system call. Ordinary variables are built into the language you are running in, will be in the same address space, and might even be in a CPU register (depending on the language and how it is executed).
It’s simply a longer trip to get the data.
That being said, it probably won’t be noticeably slow in most scenarios. Unless you’re accessing them very often (e.g. constantly using environment variables while in a tight loop, or reading them on a web server during every web request), I wouldn’t worry about the performance difference.
Edit:
Turns out the answer is, it depends:
https://stackoverflow.com/a/10636826/232593
https://stackoverflow.com/a/7460612/232593
Whether the performance difference actually matters at all or not is situational. And in all cases, you should probably measure the performance difference first for your very specific situation, before spending a lot of time worrying about it (what language? what OS? is it faster if you locally cache, etc).