英文:
How can I tell if a variable was exported or not in zsh (or bash)?
问题
在终端上，如何轻松区分以下两种情况：
- 一个shell变量：
foo=foovalue
和
- 一个导出的环境变量：
export bar=barvalue，可供子进程使用？
我知道set和env命令。set报告了两种情况，但没有指示哪个是哪个。env不报告1)。
示例终端会话
（在zsh + macOS上，但这不应该太重要）：
$foo=foovalue
$export bar=barvalue
$set | egrep "^foo|^bar"
bar=barvalue
foo=foovalue
$env | egrep "^foo|^bar"
bar=barvalue
有没有办法看到foo和bar，但也指示foo是一个仅在bash中可见的变量，对于像Python或Ruby脚本这样的子进程将不可见？通常，当我的脚本看不到我期望的内容时，我最终会查找我的shell脚本，查找变量是在哪里定义的。这样做虽然有效，但效率不高。
英文:
On the terminal how can I easily distinguish between
- a shell variable:
foo=foovalue
and
- an exported environment variable:
export bar=barvalue, usable by child processes ?
I know of set and env commands. set reports both cases, without indicating which is which. env does not report 1).
Sample terminal session
(on zsh + macos but that shouldn't matter overmuch):
$foo=foovalue
$export bar=barvalue
$set | egrep "^foo|^bar"
bar=barvalue
foo=foovalue
$env | egrep "^foo|^bar"
bar=barvalue
Any way to see both foo and bar, but also indicate that foo is a bash-only variable that will NOT be visible to child processes like a Python or Ruby script? Typically, when my scripts don't see what I expect, what I end up doing is grepping my shell scripts and looking for where the variable was defined. It works, but it's clunky at best.
答案1
得分: 3
使用 declare -p 命令并检查输出。例如：
declare -- BASH="/bin/bash"
declare -x EDITOR="vim"
很明显哪一个是已导出的，哪一个不是。
英文:
Use declare -p and inspect the output. For example:
declare -- BASH="/bin/bash"
declare -x EDITOR="vim"
It's obvious which one is exported or not.
答案2
得分: 0
variable_name="some value"
export variable_name
检查变量是否已导出：
declare -p variable_name | grep -q 'declare -x'
if [ $? -eq 0 ]; then
echo "该变量已导出。"
else
echo "该变量未导出。"
fi
英文:
variable_name="some value"
export variable_name
Check if the variable was exported:
declare -p variable_name | grep -q 'declare -x'
if [ $? -eq 0 ]; then
echo "The variable was exported."
else
echo "The variable was not exported."
fi
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