topic Re: nohup command in Operating System - HP-UX

nohup command

eric stewart — Thu, 02 Nov 2000 14:40:52 GMT

The nohup command creates the file nohup.out with -rw------- as the permissions.
We have groups of users that cover for each other but have their own login. I would like th nohup command to create the nohup.out with -rw-rw---- as the permissions.
Here was my solutions.
1. in the script that gets executed add a chmod g+rw nohup.out. The users did not wat this because it would mean work on their part.
2. create an alias nohup='>>nohup.out; chmod 660 nohup.out; /usr/bin/nohup '
The users liked this
The question I have is when I do the alias command, it shows nohup='nohup '
When I do type nohup it shows
nohup is an exported alias for nohup
Where does the nohup command alais gets set.
I can not seem to find it.
TIA

Re: nohup command

John Palmer — Thu, 02 Nov 2000 14:53:13 GMT

Hi Eric,

If you do 'man sh-posix' and search for nohup you will find that it is one of the set of exported aliases that are compiled into the shell. You can remove it with 'unalias nohup'.

Rather than creating an alias, I think that you will have more success by defining a shell function called nohup.

Regards,
John

Re: nohup command

Danny Engelbarts — Thu, 02 Nov 2000 14:54:36 GMT

Eric,

The nohup alias is compiled into ksh (see; man ksh), you can unset or redefine it though.

Greetz, Danny

Re: nohup command

James R. Ferguson — Thu, 02 Nov 2000 14:57:38 GMT

Eric:

'nohup' is one of several aliases that is compiled into the shell. It can still be redefined as you have done. If you want, you could place your alias into the user's $HOME/.profile. If the use of the alias as you have defined it is a "special case", however, I think you should consider aliasing it within the script that the users run, and NOT their global profile.

...JRF...

Re: nohup command

Victor BERRIDGE — Thu, 02 Nov 2000 14:59:36 GMT

I would use a shell, that contains:
nohup $1;
chmod 660 nohup.out

Or something like.

And use the shell as alias of nohup

Re: nohup command

eric stewart — Thu, 02 Nov 2000 15:04:51 GMT

Thanks,
The second part of the question is why do they do it for nohup? Page 4 of the man ksh shows all of the others have a default parameter set.
TIA

Re: nohup command

James R. Ferguson — Thu, 02 Nov 2000 15:44:32 GMT

Eric:

OK, second question's answer:

If you look at the nohup alias you will see that the last character of the alias value is a blank, as: nohup='nohup '. If you look at the man page for sh-posix, it notes: "If
the last character of the alias value is a blank, the word following the alias is also checked for alias substitution."

Thus, the alias as defined, allows you to use the 'nohup' command AND check the command following it for alias substitution.

...JRF...