“&"的目的是什么?在 shell 命令中? [英] What is the purpose of "&&" in a shell command?

问题描述

据我所知，在命令之后使用 & 是为了在后台运行它.

As far as I know, using & after the command is for running it in the background.

& 用法示例:tar -czf file.tar.gz dirname &

但是 && 怎么样?(示例)

推荐答案

此外，您还有 || 是逻辑或，还有 ; 只是一个不关心之前命令发生了什么的分隔符.

Furthermore, you also have || which is the logical or, and also ; which is just a separator which doesn't care what happend to the command before.

$ false || echo "Oops, fail"
Oops, fail

$ true || echo "Will not be printed"
$  

$ true && echo "Things went well"
Things went well

$ false && echo "Will not be printed"
$

$ false ; echo "This will always run"
This will always run

可以在此处找到有关此的一些详细信息命令列表 在 Bash 手册中.

Some details about this can be found here Lists of Commands in the Bash Manual.

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