bash forgets export variable

问题

I am unable to make even the simplest export of variables, from within scripts, to work in my bash - what am I dooing wrong?

File test.sh :

#!/bin/bash
echo $ttt
ttt="fffalse"
export ttt
echo $ttt

bash test :

hpek@hpek:~/temp$ export ttt="tttrue"
hpek@hpek:~/temp$ ./test.sh 
tttrue
fffalse
hpek@hpek:~/temp$ ./test.sh 
tttrue
fffalse
hpek@hpek:~/temp$ 

Edit:

I now know from the answers, that this will not work. -but how can make a single variable remembered between processes? Do I need to store it in a file?

回答1:

./test.sh is the same as bash test.sh

Each shell script running is, in effect, a subprocess (child process) of the parent shell.
And subprocess cannot export env-var to it's parent.

---

You can try this（run in the same environment）:

. test.sh

回答2:

export works in the current process and any children spawned afterward; it does not work across process boundaries (parents, existing children, unrelated processes). The environment behaves like a sort of shadow argument list, not like a filesystem or mailbox.

来源：https://stackoverflow.com/questions/10457725/bash-forgets-export-variable