bash "while :" vs. "while true"
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"while :" vs. "while true"
提问by helpermethod
When you look at how infinite loops should be implemented, you mostly see this approach:
当您查看应如何实现无限循环时，您通常会看到这种方法：
while :
do
# loop infinitely
done
But I just don't understand the use of :here. Wouldn't it be better to use:
但我就是不明白:这里的用法。使用以下方法不是更好吗：
while true
do
# loop infinitely
done
?
?
采纳答案by phoxis
from manual:
从手册：
: [arguments] No effect; the command does nothing beyond expanding arguments and performing any specified redirections. A zero exit code is returned.
：[参数]没有效果；该命令除了扩展参数和执行任何指定的重定向外，什么都不做。返回零退出代码。
As this returns always zero therefore is is similar to be used as true
由于这始终返回零，因此类似于用作 true
Check out this answer: What Is the Purpose of the `:' (colon) GNU Bash Builtin?
看看这个答案：':'（冒号）GNU Bash 内置函数的目的是什么？
回答by unwind
The colon is a built-in commandthat does nothing, but returns 0 (success). Thus, it's shorter (and faster) than calling an actual command to do the same thing.
冒号是一个内置命令，什么都不做，但返回 0（成功）。因此，它比调用实际命令来做同样的事情更短（也更快）。
