How to list all the environment variables in Linux?
如何在Linux中列出所有环境变量？
When I type the command env or printenv it gives me lots of variables, but some variables like LD_LIBRARY_PATH and PKG_CONFIG don't show up in this list.
当我输入命令env或printenv时，它给了我很多变量，但是一些变量如LD_LIBRARY_PATH和PKG_CONFIG没有出现在这个列表中。
I want to type a command that list all the environment variables including this variables (LD_LIBRARY_PATH and PKG_CONFIG)
我想输入一个列出所有环境变量的命令，包括这个变量（LD_LIBRARY_PATH和PKG_CONFIG）
3 个解决方案
#1
6
env does list all environment variables.
env列出了所有环境变量。
If LD_LIBRARY_PATH is not there, then that variable was not declared; or was declared but not exported, so that child processes do not inherit it.
如果不存在LD_LIBRARY_PATH，则不声明该变量;或者已声明但未导出，因此子进程不会继承它。
If you are setting LD_LIBRARY_PATH in your shell start-up files, like .bash_profile or .bashrc make sure it is exported:
如果要在shell启动文件中设置LD_LIBRARY_PATH，例如.bash_profile或.bashrc，请确保将其导出：
export LD_LIBRARY_PATH
#2
8
try
尝试
export LD_LIBRARY_PATH=/usr/local/lib:${LD_LIBRARY_PATH}
This will modify the variable.
这将修改变量。
To print it, type: echo $LD_LIBRARY_PATH and it should show the above value.
要打印它，请输入：echo $ LD_LIBRARY_PATH，它应显示上述值。
If you're seeing nothing when you print that, then the variable might not be set.
如果在打印时没有看到任何内容，则可能未设置该变量。
#3
1
The question in fact is a good question. when run env or printenv, the output will be the system environment, but LD_LIBRARY_PATH is not belong to.
事实上这个问题是一个很好的问题。当运行env或printenv时，输出将是系统环境，但不属于LD_LIBRARY_PATH。
For example, if you set a=1, you can't show it by env. Same as LD_LIBRARY_PATH, it is used by ld.so only(ld. so – this little program that starts all your applications)
例如，如果设置a = 1，则无法通过env显示它。与LD_LIBRARY_PATH相同，它仅由ld.so使用（ld。所以 - 这个启动所有应用程序的小程序）
#1
6
env does list all environment variables.
env列出了所有环境变量。
If LD_LIBRARY_PATH is not there, then that variable was not declared; or was declared but not exported, so that child processes do not inherit it.
如果不存在LD_LIBRARY_PATH，则不声明该变量;或者已声明但未导出，因此子进程不会继承它。
If you are setting LD_LIBRARY_PATH in your shell start-up files, like .bash_profile or .bashrc make sure it is exported:
如果要在shell启动文件中设置LD_LIBRARY_PATH，例如.bash_profile或.bashrc，请确保将其导出：
export LD_LIBRARY_PATH
#2
8
try
尝试
export LD_LIBRARY_PATH=/usr/local/lib:${LD_LIBRARY_PATH}
This will modify the variable.
这将修改变量。
To print it, type: echo $LD_LIBRARY_PATH and it should show the above value.
要打印它，请输入：echo $ LD_LIBRARY_PATH，它应显示上述值。
If you're seeing nothing when you print that, then the variable might not be set.
如果在打印时没有看到任何内容，则可能未设置该变量。
#3
1
The question in fact is a good question. when run env or printenv, the output will be the system environment, but LD_LIBRARY_PATH is not belong to.
事实上这个问题是一个很好的问题。当运行env或printenv时，输出将是系统环境，但不属于LD_LIBRARY_PATH。
For example, if you set a=1, you can't show it by env. Same as LD_LIBRARY_PATH, it is used by ld.so only(ld. so – this little program that starts all your applications)
例如，如果设置a = 1，则无法通过env显示它。与LD_LIBRARY_PATH相同，它仅由ld.so使用（ld。所以 - 这个启动所有应用程序的小程序）