有a.sh：
#!/bin/bash
foo=':bar baz:'
declare varvar=aaaaaa
export xyz=abc
echo "$foo ok"
hoge=huga env piyo=alice bash -i
运行./a.sh（|是光标，>是提示符）：
:bar baz: ok
> |
有输入：
echo "foo: '$foo'"
echo "varvar: '$varvar'"
echo "xyz: '$xyz'"
echo "hoge: '$hoge'"
echo "piyo: '$piyo'"
预期输出：
> echo "foo: '$foo'"
foo: ':bar baz:'
> echo "varvar: '$varvar'"
varvar: 'aaaaaa'
> echo "xyz: '$xyz'"
xyz: 'abc'
> echo "hoge: '$hoge'"
hoge: 'huga'
> echo "piyo: '$piyo'"
piyo: 'alice'
> |
实际输出：
> echo "foo: '$foo'"
foo: ''
> echo "varvar: '$varvar'"
varvar: ''
> echo "xyz: '$xyz'"
xyz: 'abc'
> echo "hoge: '$hoge'"
hoge: 'huga'
> echo "piyo: '$piyo'"
piyo: 'alice'
> |
如何获取$foo并$varvar正确显示？