environment variables

[tom]

Howdy guys,



I just wanted to point something out.

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(bash)
$ echo $USER
me

$ echo $HOSTNAME
the-name

(newlisp)
(env "USER")
me

(env "HOSTNAME")
nothing

And the hostname is not "nothing" :-)   ("env" doesn't return anything) Why is this?

[pjot]

Which version of newLisp are you using? Because in my Linux environment:

peter[~]$ echo $USER

peter

peter[~]$ echo $HOSTNAME

solarstriker.thuis.nl

peter[~]$ newlisp

newLISP v.9.4.5 on Linux IPv4, execute 'newlisp -h' for more info.



> (env "USER")

"peter"

> (env "HOSTNAME")

"solarstriker.thuis.nl"

>

...it works as advertised....?



Peter

[cormullion]

I don't think it works on all platforms...

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$ echo $HOSTNAME
imac.local
$ newlisp
newLISP v.9.4.5 on OSX IPv4 UTF-8, execute 'newlisp -h' for more info.
> (env "HOSTNAME")
nil


[tom]

newLISP v.9.4.8 64-bit on Linux IPv4 UTF-8

[DrDave]

I don't think it works on all platforms...

It's probably not a matter of not "working", but simply not being defined on all platforms. HOSTNAME is not a default environment variable on WIN XP, for example.



But if your platform doesn't have it, you can always define it yourself.

[Lutz]

Its also a matter of what is passed on from the environment to the newLISP process. E.g. on Mac OS X HOSTNAME is defined when in the shell but not inside newLISP. But 'exec' can be used to still retrieve it on Unix:

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> (env "HOSTNAME")
nil
> (exec "echo $HOSTNAME")
("lutzmacmini")
>

On BSD like Unices like Mac OS X use the man-page for environ to find out what is available at the shell prompt:

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$ man environ



environ is a C variable maintained by the OS and used inside newLISP to read the environment. On Windows the same C variable is maintained.