I don’t know what to do. I have an environment variable, PW_PATH,
that contains the folder names where applications can be executed
from. I want to start a particular application that is in one of
those folders. I currently use the following:
system("presort /a /nos /watch #{template[0]}") # submit the
presort to run
This works when the contents of PW_PATH are added to the PATH
variable. But I would like to avoid that if I can. I guess my
questions are: How do I first acquire the contents of PW_PATH? How
do employ the contents as a temporary addition to PATH so that system
can submit the application and it will be found and executed?
Suggestions? Comments? Observations? All are appreciated.
dvn
dkmd_nielsen wrote:
I don’t know what to do. I have an environment variable, PW_PATH,
that contains the folder names where applications can be executed
from. I want to start a particular application that is in one of
those folders. I currently use the following:
system("presort /a /nos /watch #{template[0]}") # submit the
presort to run
This works when the contents of PW_PATH are added to the PATH
variable. But I would like to avoid that if I can. I guess my
questions are: How do I first acquire the contents of PW_PATH? How
do employ the contents as a temporary addition to PATH so that system
can submit the application and it will be found and executed?
Suggestions? Comments? Observations? All are appreciated.
dvn
ENV contains all environment variables; ENV[‘PW_PATH’] is the content of
PW_PATH. So this might be sufficient:
system("#{ENV[‘PW_PATH’]/presort /a /nos /watch #{template[0]}")
hth,
Siep
On Nov 12, 2:50 pm, dkmd_nielsen [email protected] wrote:
questions are: How do I first acquire the contents of PW_PATH? How
do employ the contents as a temporary addition to PATH so that system
can submit the application and it will be found and executed?
Suggestions? Comments? Observations? All are appreciated.
dvn
First question answered: pw = ENV[‘pw_path’] I got that. But I
don’t know how to employ the contents such that when the application
is submitted via system that the o/s actually knows where to go
looking.
On Nov 12, 3:06 pm, Siep K. [email protected] wrote:
variable. But I would like to avoid that if I can. I guess my
system(“#{ENV[‘PW_PATH’]/presort /a /nos /watch #{template[0]}”)
hth,
Siep
–
Posted viahttp://www.ruby-forum.com/.
Thanks, Siep. I will give this a shot. Not sure if linux and windows/
dos will treat it the same, but I guess that’s my job to figure out.
On Nov 12, 2008, at 6:22 PM, dkmd_nielsen wrote:
the search path of PATH.
Is that better?
you can always store the path before and reset it after the system call:
old_path = ENV[‘path’]
ENV[‘path’] << ENV[‘PW_PATH’]
system(…)
ENV[‘path’] = old_path
dvn
regards,
Let’s provide more information. The contents of pw_path include this:
C:\PW\firstprep;C:\PW\rapid\docs;C:\PW\la;C:\PW\rapid;c:\pw\pst;
And the application I want to execute is presort.exe, which is located
in c:\pw\pst;
I would like to be able to tell the O/S you have to look in the above
folders to find presort.exe, just as you would using PATH. In a
sense, I would like to temporarily merge the contents of pw_path into
the search path of PATH.
Is that better?
dvn
On Nov 12, 2008, at 10:30 PM, Rob B. wrote:
Of course, doing that kind of thing in Ruby should look like:
begin
old_path = ENV[‘path’]
ENV[‘path’] << ENV[‘PW_PATH’]
system(…)
ensure
ENV[‘path’] = old_path
end
totally right… although, I don’t think that system will raise an
exception. Maybe if PATH is blank (i.e. nil), concatenating the other
environmental variable will raise an exception.
-Rob
Rob B. http://agileconsultingllc.com
[email protected]
regards,
On Nov 12, 2008, at 7:20 PM, Rolando A. wrote:
I would like to be able to tell the O/S you have to look in the above
ENV[‘path’] << ENV[‘PW_PATH’]
system(…)
ENV[‘path’] = old_path
dvn
regards,
Rolando A. M.
Of course, doing that kind of thing in Ruby should look like:
begin
old_path = ENV[‘path’]
ENV[‘path’] << ENV[‘PW_PATH’]
system(…)
ensure
ENV[‘path’] = old_path
end
-Rob
Rob B. http://agileconsultingllc.com
[email protected]
On Nov 13, 2008, at 11:42 AM, Yossef M. wrote:
Maybe you mean ENV[‘path’] += ENV[‘PW_PATH’], or maybe you mean
old_path = ENV[‘path’].dup
oops… you’re right (I always forget about this! I even wrote a
question about this for the ruby-basic java black belt[1]
certification test :-P)
Second, paths have separators, so simply sticking two different path
strings together is going to make something strange at the join.
yes sir, I skip those on purpose… 
(it was too late and it was
the last email I wrote before going to bed. I think that the OP should
know that PATH is a list of directories that are separated by
something, or at least he has the notion, so I only provided an idea
on how to solve his problem, not a complete solution, which, IMHO is
the best thing, because when you provide a complete solution, most
people stick to that and don’t think too much around it).
Anyway, you should add the path like this:
ENV[‘PATH’] += “;#{ENV[‘PW_PATH’]}” # just in case ENV[‘PW_PATH’] is nil
even if PATH has a “;” at the end, it does no harm to have another one.
Third, I think you mean ENV[‘PATH’], not ENV[‘path’].
That’s also correct.
HTH HAND
-yossef
[1]
http://www.javablackbelt.com/QuestionnaireDefDisplay.wwa?questPublicId=01548
regards,
On Nov 12, 6:20 pm, Rolando A. [email protected] wrote:
you can always store the path before and reset it after the system call:
old_path = ENV[‘path’]
ENV[‘path’] << ENV[‘PW_PATH’]
system(…)
ENV[‘path’] = old_path
First,
str = ‘blah’
=> “blah”
old_str = str
=> “blah”
str << ‘test’
=> “blahtest”
str
=> “blahtest”
old_str
=> “blahtest”
Maybe you mean ENV[‘path’] += ENV[‘PW_PATH’], or maybe you mean
old_path = ENV[‘path’].dup
Second, paths have separators, so simply sticking two different path
strings together is going to make something strange at the join.
Third, I think you mean ENV[‘PATH’], not ENV[‘path’].
HTH HAND