[英]Empty enviroment variable name
I'm debugging an application in Ubuntu 20.04 with:我正在调试 Ubuntu 20.04 中的应用程序:
ltrace -e getenv ./cmd
I want to know which enviroment variables and their respective values are involved.我想知道涉及哪些环境变量及其各自的值。 I got surprised when I realized that there is an "empty name variable" without a value.当我意识到有一个没有值的“空名称变量”时,我感到很惊讶。 There is the ltrace output:有 ltrace output:
....
linux_a64.installos->getenv("") = nil
linux_a64.installos->getenv("TMPDIR") = "/tmp"
linux_a64.installos->getenv("DEBUGCMD") = nil
....
Does anyone knows what this could be?有谁知道这可能是什么? There is a way to give an empty value to a enviroment variable?有一种方法可以给环境变量一个空值吗?
Probably this environment variable wasn't set yet.可能尚未设置此环境变量。
$ env | grep POTATO
$ echo $POTATO
You can get the environment variable value, even if that wasn't set before..您可以获得环境变量值,即使之前没有设置。
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