Is there a way to find the PostgreSQL installation directory (bin) via query?
Thanks.
2
-
I'm afraid to ask what do you want to do. It sounds like a bad idea.Luc M– Luc M2011-09-15 20:25:10 +00:00Commented Sep 15, 2011 at 20:25
-
Ideas are never good or bad, intentions are. I need to know the path of bin directory via query, and then use it in the frontend. Since users can install postgresql in any directory they desire, I cannot hardcode it. :)Nick Binnet– Nick Binnet2011-09-15 20:30:07 +00:00Commented Sep 15, 2011 at 20:30
Add a comment
|
5 Answers
I don't think there is a way to get the path of the Postgres executable.
The only thing that can be retrieved from the system catalogs is the location of the data directory.
SELECT *
FROM pg_settings
WHERE name = 'data_directory'
This can only be executed by the superuser though.
3 Comments
Nick Binnet
Yes, I have already done that. select * from pg_settings order by length(setting) desc;
Nick Binnet
Is it safe to assume that bin directory will be stored relatively in all installation cases?
I would simply create a table and save the info you want in it as part of your installation procedure.
2 Comments
Bohemian
If you don't control the installation, why do you care? (You should not care)
Bohemian
I would suggest that you create the table just like all your other tables for your app, but also ship your customers a script they can run that will detect the bin path and update/insert the appropriate data, including creating the table if that's appropriate
On a Linux system, there will be a /etc/init.d/postgresql script file (possibly with a trailing version number) in which there is a PGENGINE configuration variable which specifies the bin directory, like: PGENGINE=/usr/bin. Other config variables there may also be of interest.
Comments
You can get the process identifier of the backend (=postgres process) using:
select pg_backend_pid();
How to determine the executable path for a process identifier depends on your OS. On Linux you can just do realpath /proc/12345/exe
Comments
Building on Jakob's answer, this is how I did it using psql:
psql -t -c '\o | xargs -I {} realpath /proc/{}/exe | xargs dirname' -c 'select pg_backend_pid()' -c 'select pg_sleep(1)'
