BASH通配符:选择所有变量(而非内容) [英] BASH Wild-card : Select all variables (not the content)

问题描述

我有一堆要检查的变量，如果它们包含值"None"，那么我想清空它们.

I have a bunch of variables that I want to check, and if they contain the value "None" then I want to empty them.

    var1=(check for some value, sometimes it returns "none")
    var2=(check for some value, sometimes it returns "none")
    var3=(check for some value, sometimes it returns "none")
    someBizzareName=(check for some value, sometimes it returns "none")

    if [[ "${var1}" == "None" ]] ; then
        var1=""
    fi
    if [[ "${var2}" == "None" ]] ; then
        var2=""
    fi

这一切都很好，很花哨，只是因为我有很多 varN，如果[[" $ {varN}"==无"]] 和，我必须知道他们的名字；所以我想知道，由于搜索和匹配所有内容在BASH中非常自然，如果变量在for循环内中有通配符，那么将匹配 all vars，类似 $ {*} (我尝试过，行不通)吗?我进行了各种各样的搜索，但是总是找到有关匹配变量 content 的信息，而不是var本身..?

And this is all working fine and dandy, only since I have a lot of varN, I will end up with a ton of if [[ "${varN}" == "None" ]] and I have to know their names ; so I was wondering, since it's in BASH very nature to search and match everything, if there is a wild-card for variables, inside a for loop, that will match all vars, something like ${*} (I tried that, does'nt work) ? I have done all kinds of searches but always find something about matching variable content, not the var itself..?

推荐答案

全部，否.但是您可以匹配模式(但不能匹配 * ).

All, no. But you can match a pattern (but not *).

$ echo "${!B*}"
BASH BASHOPTS BASHPID BASH_ALIASES BASH_ARGC BASH_ARGV BASH_CMDS BASH_COMMAND BASH_LINENO BASH_SOURCE BASH_SUBSHELL BASH_VERSINFO BASH_VERSION

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