两个.bashrc命令之间的差异

Question

I have this line of code :

[ -x /usr/bin/lesspipe ] && eval "$(SHELL=/bin/sh lesspipe)"

Is there a difference between

• eval "$(SHELL=/bin/sh lesspipe)"

and more simply

• SHELL=/bin/sh lesspipe (or export SHELL=/bin/sh lesspipe )

(What is the difference between using export and not using it by the way?)

Answer 1

Yes, there's a difference.

The second example just runs lesspipe with the SHELL variable set to /bin/sh in its environment.

The first example does the same, but takes the output and runs that as a command in your current shell.