Linux 输出重定向符号 `>!` 是啥意思?

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这是一个创建于 3730 天前的主题，其中的信息可能已经有所发展或是发生改变。

从 .oh-my-zsh/tools/check_for_upgrade.sh 看到的:

https://github.com/robbyrussell/oh-my-zsh/blob/master/tools/check_for_upgrade.sh#L8

```
echo "LAST_EPOCH=$(_current_epoch)" >! ~/.zsh-update
```

单独的>, 两个>> 都见过. >! 第一次见. Google 不到

zsh

定向

符号

4 条回复 • 2014-09-09 10:40:15 +08:00

paulw54jrn

2014-09-09 08:15:55 +08:00

搬运http://zsh.sourceforge.net/Doc/Release/Redirection.html

>| word
>! word
Same as >, except that the file is truncated to zero length if it exists, even if CLOBBER is unset.

yangg

2014-09-09 09:16:12 +08:00

@paulw54jrn Is it zsh only?

pfitseng

2014-09-09 09:28:52 +08:00

http://en.wikipedia.org/wiki/Clobbering

$ echo "Hello, world" >file.txt
$ echo "This will overwrite the first greeting." >file.txt
$ set -o noclobber
$ echo "Can we overwrite it again?" >file.txt
-bash: file.txt: cannot overwrite existing file
$ echo "But we can use the >| operator to ignore the noclobber." >|file.txt
$ # Successfully overwrote the contents of file.txt using the >| operator
$ set +o noclobber # Changes setting back

ETiV

2014-09-09 10:40:15 +08:00

@paulw54jrn
@pfitseng

懂了! thanks