Get env variable

[fabien]

Hi!

I would like to check that some variables in the environment are set properly or simply exists.

If I do:
"set test $env(VAR)" and VAR does not exist I get an error message "VAR in not ENV array" How can I go pass this if VAR does not exist and I still want to be able to run the program and exit with my own error message.

I could go through all the elements of ENV array and check each one but I am sure there is a better way to do this.

Thanks!

 

[ulis]

You can do:

  catch { set test $env(VAR); puts $test }
  if {[info exists env(VAR)]} { puts $env(VAR) }

The first line catches the fired error if env(VAR) does not exist.
The second line tests explicitely for existance of env(VAR).

ulis

 

[Bong]

I think you'll find "catch" is what you want. For example:

%set abc
can't read "abcv": no such variable
%set rtc [catch {set abc}]
1
%set abc 5
5
%set rtc [catch {set abc}]
0 Bob Rashkin
rrashkin@csc.com

 

[fabien]

thanks Ulis this worked fine!