I'd like to make an alias of commands which contains the command newgrp.
exple:
alias my_cmde newgrp toto; my_pg &

this line doesn't work. why ?
Thanks for your help

How aliases work depends on your shell. How newgrp works depends on your version of unix. You need to mention a few specifics to get a useful answer.

But for the most part newgrp is obsolete. It was useful in the 70's and early 80's. But now you can be a member of several groups at once. Type "groups" to see your groups. I doubt that anyone has rewritten newgrp to work sensibly in an environment where users belong to multiple groups. I'm not even sure what work sensibly would mean. Should it revoke your membership in all other groups? Add a group to the list? What if you were already a member of the max number of groups?

In fact, to work on several project, in a same UNIX group, we make sub-group. If we change the project we were working on, we have to change the group, so we use for exple: newgroup my-project.
I work on SUN-OS 5.7
As I said, I want in one hand, to make an alias to launch applications, when I start working on this project.
Thanks for your help.