环境变量使用

[tanuki@localhost python_study]$ cat /etc/profile |tail -3
TMOUT=1800
export PATH=/home/tanuki/python_study:$PATH

[tanuki@localhost python_study]$ pwd
/home/tanuki/python_study
[tanuki@localhost python_study]$ ll
total 8
-rwxrw---x 1 tanuki tanuki 325 Jun 4 19:18 for.sh
-rwxrw---x 1 tanuki tanuki 325 Jun 4 19:47 set_login
[tanuki@localhost python_study]$ set_login
please insert a number: 20
the 20 is right!
[tanuki@localhost python_study]$