On Sat, Jul 20, 2024 at 06:30:42 +0800, p...@gmx.it wrote: > On 2024-07-20 06:25, Greg Wooledge wrote: > > > > > > I can not clearly understand for this statement. what's "future shell > > > commands"? can you show an example? > > > > hobbit:~$ unset -v VAR > > hobbit:~$ VAR=bar; ./a.sh > > I am a.sh, and inside me, VAR=<>. > > hobbit:~$ echo "VAR=<$VAR>" > > VAR=<bar> > > OK I know that. $VAR can be seen by future shell command in this > session, but cannot be seen by a sub-shell such as a.sh.
a.sh is NOT a subshell. That's really super important. a.sh is a NON-subshell child process. In an actual subshell, you *would* see the variable, because subshells inherit regular variables as well as environment variables. hobbit:~$ unset -v VAR hobbit:~$ VAR=foo; (echo "I am a subshell, and VAR=<$VAR>") I am a subshell, and VAR=<foo> hobbit:~$ ./a.sh I am a.sh, and inside me, VAR=<>. https://mywiki.wooledge.org/SubShell
