Bash 的 $_ 变量未扩展 [暂停]

Question

The $_ variable, which should expand with the arguments of the last executed command in Bash, contains _lp_runtime_before . No matter how many times I run a command, that would be the content it has. Why?

Answer 1

Actually, $_ expand to the last argument of the last command line, according to the man page of bash :

[$_] expands to the last argument to the previous command, after expansion.

If you want the whole arguments, use ::* :

$ ls -a -l -h test
[blah blah]
$ last_command="!:*" > /dev/null

$ echo $last_command
-a -l -h test

I added a redirection of stdout to null device to prevent bash to print the expansion.