Determining PostgreSQL's port

Question

I know that by default PostgreSQL listens on port 5432, but what is the command to actually determine PostgreSQL's port?

Configuration: Ubuntu 9.10 with PostgreSQL 8.4

ptman · Accepted Answer · 2023-05-12T06:35:03.637

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lsof and nmap are solutions, but they're not installed by default. What you want is netstat(8).

sudo netstat -plunt |grep postgres

And if you don't have netstat, but have ss

sudo ss -pln |grep postgres

edited May 12 '23 at 06:35

answered Mar 01 '10 at 15:25

ptman

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Linux is supposedly migrating away from route/ifconfig/netstat. The equivalent modern command is `ss -plung|grep postgres` (note, same flags) – ptman Feb 22 '17 at 12:11
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There is no `g` flag anymore for the `ss` command. Try: `ss -pa |grep postgresql` – GrayedFox Jun 14 '18 at 08:06
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@GrayedFox thanks for the update, but for me that gives the name of the port, not the number, so I think `ss -pan |grep postgres` is more suitable – ptman Jun 14 '18 at 12:58
`netstat` is not installed by default nowadays – Flimm May 11 '23 at 17:04
@Flimm indeed, the other comments point to `ss` – ptman May 12 '23 at 06:32

score 16 · Answer 2 · answered Jul 12 '12 at 18:43

The PostgreSQL utility pg_lsclusters shows information about the configuration and status of all clusters, including the port number.

$ pg_lsclusters
Version Cluster   Port Status Owner    Data directory                     Log file
8.4     main      5433 online postgres /var/lib/postgresql/8.4/main       /var/log/postgresql/postgresql-8.4-main.log

This also has the advantage of not requiring 'sudo' privileges to run.

On Debian and Ubuntu systems, the pg_lsclusters command is provided by the package postgresql-common, which should be installed by default with the postgresql server.

Note that `pg_lsclusters` is an Ubuntu-ism, and is *not* a standard Postgres command. It will work for this case, but is not a general-purpose solution... — voretaq7, Oct 11 '12 at 20:45

score 5 · Answer 3 · answered Mar 01 '10 at 14:34

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If you want to do it from inside the database, just do "SHOW port". But that assumes you've been able to connect to it, at least locally...

answered Mar 01 '10 at 14:34

Magnus Hagander

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score 2 · Answer 4 · answered Mar 01 '10 at 13:50

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If you are searching on the local machine, I would use the lsof command to check for the port postgresql is using

lsof -p <postgres_process_id>

answered Mar 01 '10 at 13:50

Dominik

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You may have to run this as root. – Michael Mior Mar 01 '10 at 15:19

score 2 · Answer 5 · answered Mar 01 '10 at 14:04

I have machines with multiple postgres instances running -- and so I also have the issue of trying to match up the correct database with each port. I tend to do:

$ ps aux | grep  postgres | grep -v 'postgres:'

And then, for each of instances returned look for the directory (-D argument) and:

$ sudo grep port $DIR/postgresql.conf

score 1 · Answer 6 · answered Mar 01 '10 at 13:41

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Here's one solution that I've found:

sudo apt-get install nmap
sudo nmap localhost | grep postgresql

If you're wanting to search a non-local machine, just change localhost to the server's IP address.

answered Mar 01 '10 at 13:41

Matthew Rankin

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Determining PostgreSQL's port

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