寻找可以执行与 echo 相同的操作的外部命令

Question

echo是 bash 内置的。是否有一个外部命令可以做同样的事情echo？（可以做更多）

Answer 1

有echo：

$ /bin/echo --version
echo (GNU coreutils) 8.25
Copyright (C) 2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by Brian Fox and Chet Ramey.

不改变 shell 状态的 shell 内置命令也经常被实现为外部命令 - [/test是一个著名的命令，所以是printf：

$ /bin/printf --version
printf (GNU coreutils) 8.25
Copyright (C) 2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by David MacKenzie.

如果有busybox，它也可能支持echo：

$ busybox echo --version
--version