使用 Bash 自动将上一个命令的输出捕获到变量中? [英] Automatically capture output of last command into a variable using Bash?
问题描述
我希望能够在后续命令中使用上次执行命令的结果.例如,
I'd like to be able to use the result of the last executed command in a subsequent command. For example,
$ find . -name foo.txt
./home/user/some/directory/foo.txt
现在假设我希望能够在编辑器中打开文件,或者删除它,或者用它做其他事情,例如
Now let's say I want to be able to open the file in an editor, or delete it, or do something else with it, e.g.
mv <some-variable-that-contains-the-result> /some/new/location
我该怎么做?也许使用一些 bash 变量?
How can I do it? Maybe using some bash variable?
更新:
澄清一下,我不想手动分配东西.我所追求的是类似于内置 bash 变量的东西,例如
To clarify, I don't want to assign things manually. What I'm after is something like built-in bash variables, e.g.
ls /tmp
cd $_
$_
保存上一个命令的最后一个参数.我想要类似的东西,但要输出最后一个命令.
$_
holds the last argument of the previous command. I want something similar, but with the output of the last command.
最终更新:
Seth 的回答非常有效.需要牢记以下几点:
Seth's answer has worked quite well. Couple of things to bear in mind:
- 第一次尝试解决方案时不要忘记
触摸/tmp/x
- 只有在最后一个命令的退出代码成功时才会存储结果
推荐答案
这是一个非常棘手的解决方案,但它似乎在某些时候大部分时间都有效.在测试期间,我注意到在命令行上获取 ^C 时它有时不能很好地工作,尽管我确实对其进行了一些调整以使其表现得更好一些.
This is a really hacky solution, but it seems to mostly work some of the time. During testing, I noted it sometimes didn't work very well when getting a ^C on the command line, though I did tweak it a bit to behave a bit better.
这个 hack 只是一个交互模式的 hack,我非常有信心我不会向任何人推荐它.后台命令可能会导致比正常情况更不明确的行为.其他答案是以编程方式获得结果的更好方法.
This hack is an interactive mode hack only, and I am pretty confident that I would not recommend it to anyone. Background commands are likely to cause even less defined behavior than normal. The other answers are a better way of programmatically getting at results.
话虽如此,这是解决方案":
That being said, here is the "solution":
PROMPT_COMMAND='LAST="`cat /tmp/x`"; exec >/dev/tty; exec > >(tee /tmp/x)'
设置此 bash 环境变量并根据需要发出命令.$LAST
通常会有你要找的输出:
Set this bash environmental variable and issues commands as desired. $LAST
will usually have the output you are looking for:
startide seth> fortune
Courtship to marriage, as a very witty prologue to a very dull play.
-- William Congreve
startide seth> echo "$LAST"
Courtship to marriage, as a very witty prologue to a very dull play.
-- William Congreve
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