topic Re: Time Output in Operating System - HP-UX

Time Output

Chin Jin Kiat — Thu, 25 Mar 2004 23:25:31 GMT

This is boggling, any explanation would be much appreciated.

On a server, running the following:

# ssh username@hostA "env | grep TZ"

... produces no result, yet:

# ssh username@hostA "echo $TZ"

gives the timezone. How can the TZ variable be set and yet not reflected in "env"?

Re: Time Output

Steven E. Protter — Thu, 25 Mar 2004 23:32:45 GMT

I not an expert on this aspect.

Try this though:

Try loading the environment in the command line

ssh username@hostA "./etc/profile;.$HOME/.profile;env | grep TZ"

I'm interested in the result. Seeme the environment appears not fuly loaded
I've had to do environment loads prior to running scripts in ssh mode. There may be a command line option to force the load. I'm checking.

SEP

Re: Time Output

Sanjiv Sharma_1 — Fri, 26 Mar 2004 00:07:47 GMT

Hi Chin,

Please check this link:
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=78306

hth.

Re: Time Output

Chin Jin Kiat — Fri, 26 Mar 2004 02:57:26 GMT

Hi,

Thanks so far but it didn't help situation.

To further elaborate:

1. Both commands essentially does a ssh connection to "hostA" and runs the command "env| grep TZ" and "echo $TZ".

2. Now, if TZ was not set in one case, as shown by "env | grep TZ", it should not show not show up in the 2nd command either via "echo $TZ". Which is the bit which I have no explanation for.

Re: Time Output

Chin Jin Kiat — Fri, 26 Mar 2004 03:11:29 GMT

Stev,

Your suggestions gave me further ideas for testing.

# ssh username@hostA ". /etc/profile;. $HOME/.profile;env | grep TZ"

>> Shows TZ in "env".

ssh username@hostA ". $HOME/.profile;env | grep TZ"

>> TZ setting in "env" is gone.

Still probing, thanks for all help so far.

Re: Time Output

Jdamian — Fri, 26 Mar 2004 03:17:45 GMT

The answer to your question is:

A variable only is listed by 'env' command when that variable has been exported. For instance, see carefully the two next examples:

# first example. Output is empty
HPHPHP=hello
env | grep '^HPHPHP'

# second example. Output is
export HPHPHP=hello
env | grep '^HPHPHP'
HPHPHP=hello

Other issue is what your second command line prints a TZ value. This is due because that value is not from 'hostA', but from the computer you launch the ssh command (let's call it 'myhost'). Before running the ssh, shell running in 'myhost' substitutes "$TZ" for its value, then (for instace TZ variables contains the value UTC),the command executed is:

# ssh username@hostA "echo UTC"

To see the value of TZ variable in hostA you should use single quotes instead:

# ssh username@hostA 'echo $TZ'

I hope this be useful.