سلام
توو help اوبونتو اومده :
Setenv
======
 - Command: setenv var string
     (none)
     Set the environment variable VAR to value STRING.  If only VAR is
     specified, the user will be prompted to enter a value.  If no
     parameters are specified, the user will be prompted for both
     variable and value. The environment is inherited by all
     subsequently forked shells.
 - Command: unsetenv var
     (none)
     Unset an environment variable.
ولی وقتی setenv یا unsetenv رو می زنم میگه:
bash: setenv: command not foundیا
bash: unsetenv: command not found
مشکل از کجاست؟