[adeel123]

hi,
there is a file whichh is basically a executable file (NMON). till now only root user can run that file being an owner of that file. now i wanted to give permision to another user that is user1 that he can also execute nmon file which is in /usr/bin but no 1 else can run that.
for that i was trying chown command but how can i add both the users that is root and user1 in 1 command of chown.
if i m wrong kindly suggest me wht to do to allow them only.
rite now this is the permision set to that file.

DR-U-HR-DB: /usr/bin # ls -al nmon
-rwxr----- 1 root staff 539536 Jul 14 17:34 nmon

[ross.mather]

A file only belongs to one user. I cannot belong to more than one user. Each file has rights for the owning user in this case root, the owning group - in this case staff, and all other users.

What you are truying to do needs to be done using the group permissions. It can be done simply by:
mkgroup users=root,user1 nmongrp
chown root:nmongrp /usr/bin/nmon
chmod 750 /usr/bin/nmon